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HANDBOOK 


practice  and  girt 


PHOTOGRAPHY 


BY 


DR.   HERMANN  VOGEL, 

TEACHER  OF  PHOTOGRAPHY  AT  THE  ROYAL  TECHNICAL  ACADEMY  AT  BERLIN;  PRESIDENT 
OF  THE  SOCIETY  FOR  THE  PROMOTION  OF  PHOTOGRAPHY  AT  BERLIN;  EDITOR  OF 
THE  "  PHOTOGRAPHISCHEN  MITTHEILUNGEN  j"  MEMBER  OF  THE  INTER- 
NATIONAL JURY  OF  THE  PARIS  EXHIBITION  OF  1867,  AND  THE 
VIENNA  EXPOSITION  OF  1873;  HONORARY  MEMBER  OF 
THE  NATIONAL  PHOTOGRAPHIC  ASSOCIATION 
OF  THE  UNITED  STATES. 


SECOND  EDITION, 

ENLARGED,  REVISED,  AND  CORRECTED  BY  THE  AUTHOR,  AND 
ESPECIALLY  ADAPTED  FOR  THE  UNITED  STATES. 


IftxmslnM  from  tft*  <&mnm. 


PHILADELPHIA: 
BENERMAN  &  WILSON,  PUBLISHERS. 
187  5. 


Entered  according  to  Act  of  Congress,  in  the  year  1875, 
By  BENERMAN  &  WILSON, 
the  Office  of  the  Librarian  of  Congress,  at  Washington,  T. 


SHERMAN  &  CO.,  PRINTERS, 
PHILADELPHIA. 


fHt.  COWER 
i  i.  MSi 


PREFACE 

TO  THE  SECOND  GEKMAN  EDITION. 


The  first  edition  of  this  work  met  with  a  more  rapid  sale  than  I 
dared  to  hope,  and  the  leniency  of  the  public  gives  me  the  conviction 
that  in  spite  of  the  shortcomings  in  the  arrangement  and  the  contents, 
which  are  well  known  to  me,  I  have  come  up  to  the  requirements  of 
the  times  ;  at  the  same  time  I  feel  it  obligatory  to  change  the  second 
edition  in  such  a  manner  as  to  do  full  justice  to  the  wants  of  the  public. 

Considering  the  ceaseless  progress  of  photography  this  task  was  not 
an  easy  one.  Whole  chapters  had  to  be  rewritten  and  rearranged,  and 
everywhere  the  abundance  of  new  material  had  to  be  put  in  its  proper 
place.  In  some  parts  of  the  book  not  a  vestige  of  the  old  work  has  been 
left,  as  those  will  readily  observe  who  closely  scrutinize  the  chapters  on 
Photography  with  Chromic  Salts,  the  Changes  of  the  Silver  Picture,  the 
Alkaline  Development,  the  Collodion,  the  Arrangement  of  the  Gallery, 
the  Chemical  Action  of  Color,  Dry  Plates,  Enlargements,  Carbon  Pro- 
cess, the  Keproduction  of  Negatives,  the  Transfer  Process,  Perspective, 
Pose,  and  Standpoint,  etc.,  etc. 

The  size  Of  the  work  has  been  much  increased.  I  should  have  much 
liked  to  introduce  the  new  chemical  symbols  in  place  of  the  old  ones, 
but  experience  has  taught  me  that  the  practical  workers,  and  these  are 
the  majority  of  our  readers,  are  scarcely  familiar  with  the  new  symbols, 
and  therefore  the  old  symbols  are  retained  in  this  edition. 

The  retouch  has  only  been  treated  superficially,  as  this  subject  has 
been  fully  treated  by  Mr.  Hartman  in  the  third  edition  of  Grasshoff's 
Retouch. 

May  the  book  in  its  new  dress  meet  with  the  same  favorable  reception 
which  was  awarded  to  the  first  edition. 


Professor  Dr.  H.  Vogel. 


PREFACE 

TO  THE  SECOND  AMERICAN  EDITION. 


The  second  American  edition  of  my  book  has  been  entirely  remod- 
elled so  as  to  meet  the  requirements  of  the  age.  The  material  has  been 
increased  and  carefully  revised.  Of  new  chapters  I  mention  only  the 
Negative  Retouch,  which  was  left  out  in  the  first  German  and  American 
editions  ;  also  numerous  hints  on  Paper,  Collodion,  Landscape  Photog- 
raphy, etc. 

May  the  book  meet  with  the  same  favorable  reception  as  the  first  edi- 
tion and  the  Reference-book. 

Professor  Dr.  H.  Vogel. 


INTRODUCTION. 


A  careful  study  of  the  history  of  invention  will  show  but  few  periods 
as  rich  in  new  ideas  and  facts  as  the  past  hundred  years. 

With  the  rise  of  the  explaining  natural  sciences — chemistry  and  natu- 
ral philosophy — commenced  a  new  era  by  applying  the  discoveries  to 
actual  life  and  industrial  pursuits.  Thus  originated  the  steam  engine, 
gas,  sulphuric  acid,  the  manufacture  of  soda,  beet-root  sugar,  the  manu- 
facture of  ultramarine,  not  to  mention  numerous  other  things  in  which 
the  physical  or  chemical  action  of  heat  was  used  in  a  new  form. 

In  an  analogous  manner  we  see  another  of  the  natural  forces,  formerly 
unused,  enter  as  an  active  agent  into  our  industry, — electricity.  Weber 
created  the  electro-magnetic  telegraph;  Jacoby  the  galvanoplastic  process. 

Finally,  the  present  age  brought  forth  an  art  in  which  the  chemical 
action  of  light  is  the  principal  agent.  This  art  is  Photography.  It  has 
existed  only  twenty-five  years,  and  still  we  may  say  that  no  invention  of 
this  century  has  since  its  first  appearance  experienced  such  a  gigantic 
development  and  exercised  so  powerful  an  influence  on  our  social,  artis- 
tic, and  scientific  relations  as  this  one.  At  first  a  mere  method  of  taking 
portraits,  its  application  has  now  extended  to  almost  all  the  branches  of 
human  knowledge  and  science.  It  supplies  a  natural  self-print  in  the 
widest  sense  of  the  word, — it  furnishes  the  naturalist  with  faithful  rep- 
resentations of  animals,  plants,  and  minerals ;  the  geographer  obtains 
from  it  the  basis  from  which  to  develop  his  maps ;  it  makes  for  the  engi- 
neer in  a  few  moments  faithful  copies  of  the  most  complicated  machinery, 
and  reproductions  of  his  drawings  and  plans,  which  would  occupy  the 
time  of  the  most  skilful  draughtsman  for  weeks ;  it  supplies  him  with  an 
authentic  foundation  for  the  construction  of  plans  and  maps ;  it  is  em- 
ployed successfully  in  lithography  and  porcelain  painting ;  it  serves  the 
artist  for  multiplying  his  productions,  and  places  copies  of  inimitable 
truthfulness  at  a  moderate  price  within  the  reach  of  all ;  it  is  as  impor- 
tant an  auxiliary  for  developing  a  taste  for  art  in  the  people  as  the  in- 
vention of  printing  is  for  the  dissemination  of  knowledge. 

Let  us  briefly  consider  how  this  art  developed  itself.  There  are  many 
inventions  which  originated  by  accident,  by  the  favor  of  the  moment ;  as 
instances,  we  may  mention  gunpowder,  the  deflection  of  the  magnetic 
needle  by  the  galvanic  current,  and  the  telescope ;  but  others  required 
years  of  thoughtful  study  and  experiment  before  they  could  take  their 
place  amongst  the  inventions.    Photography  belongs  to  the  latter  class. 

It  was  long  known  that  chloride  of  silver  would  turn  dark  on  being 
exposed  to  light.  It  was  also  known  that  paper,  the  skin,  etc.,  when 
wetted  with  a  solution  of  silver,  would  be  discolored  by  the  light  of  the 
sun.  But  only  in  the  beginning  of  this  century  the  idea  was  conceived 
to  use  these  facts  for  the  production  of  pictures  by  the  agency  of  light. 

Two  Englishmen,  Davy  and  Wedgwood,  made  the  first  experiments 


vi 


INTRODUCTION. 


of  the  kind  in  the  year  1802.  They  placed  a  piece  of  paper  in  a  solution 
of  silver,  brought  it  into  contact  with  an  opaque  object — for  instance,  a 
silhouette — and  exposed  it  to  sunlight.  All  that  part  of  the  paper  not 
covered  by  the  silhouette  turned  brown  by  the  action  of  light ;  the  bal- 
ance of  the  paper  remained  white;  thus  a  white  picture  on  a  brown 
ground  was  produced.    This  was  the  first  light  picture. 

Unfortunately  these  pictures  were  not  permanent.  The  part  which 
remained  white  soon  darkened  by  the  action  of  diffused  light,  and  finally 
the  picture  disappeared  by  the  influence  of  the  same  agency  to  which  it 
owed  its  origin. 

Davy  photographed  in  this  manner  the  image  of  the  solar  microscope. 

Almost  simultaneously  with  Davy  and  Wedgwood,  a  Frenchman,  by 
the  name  of  Niepce,  entertained  the  idea  of  making  pictures  by  the 
agency  of  light. 

From  the  year  1814  he  worked  incessantly ;  he  experimented  for  years, 
but  approached  only  step  by  step  to  the  desired  end, — the  production  of 
permanent  pictures  by  the  agency  of  light. 

While  by  the  method  of  Wedgwood  and  Davy  only  flat  objects,  which 
could  be  placed  in  close  contact  with  the  sensitive  paper,  such  as  leaves, 
drawings,  etc.,  permitted  of  being  copied  by  the  process,  M.  Niepce 
aimed  to  obtain  representations  of  all  kinds  of  objects  in  nature, — por- 
traits, landscapes,  etc.  By  the  aid  of  the  camera  obscura,  which  the 
physicist  Porta  invented  in  the  sixteenth  century,  he  succeeded  in  this. 

Wedgwood  had  already  the  idea  to  fix  the  charming  pictures  of  this 
instrument  on  his  paper,  but  it  was  not  sensitive  enough.  Niepce  re- 
sorted to  another  preparation  sensitive  to  light, — namely,  a  solution  of 
asphaltum  in  oil  of  lavender.  With  such  a  solution  he  coaled  a  metal 
plate  and  exposed  it  for  hours  in  the  camera.  The  places  which  had 
been  exposed  to  light  became  insoluble,  and  in  the  after-treatment  with 
ethereal  oils  remained  on  the  plate  and  formed  a  picture. 

By  this  process  Niepce  produced  imperfect  light  pictures  as  far  back  as 
1826— the  so-called  heliographs— but  the  production  was  too  difficult  and 
complicated  to  give  it  great  practical  value. 

In  the  year  1829  Niepce  joined  Daguerre,  who  was  working  in  the 
same  direction.  The  two  labored  together  until  the  year  1833,  when 
Niepce,  full  of  grief  over  his  twenty  years  of  unsuccessful  toil,  died.  Da- 
guerre became  the  sole  heir  of  his  ideas,  and  a  few  years  after  ISTiepce's 
death  the  great  problem,  to  produce  by  the  agency  of  light  a  permanent 
picture  in  an  easy  and  practical  manner,  was  solved.  In  the  year  1838  he 
placed  the  first  proofs  of  his  process  before  three  members  of  the  French 
Academy,— Humboldt,  Biot,  and  Arago. 

The  excitement  was  immense  ;  everybody  was  anxious  to  learn  how 
these  pictures  were  made.  Arago  induced  Daguerre  to  publish  his  in- 
vention, and  the  Government  granted  him  a  pension  of  six  thousand 
francs.  At  the  same  time  a  pension  of  four  thousand  francs  was  granted 
to  the  son  of  M.  Niepce.  On  the  19th  of  August,  1839,  the  secret  of  the 
production  of*  these  pictures  was  given  to  the  world  in  the  public  session 
of  the  Academy.    The  concourse  was  enormous.    All  the  votaries  of 


INTRODUCTION. 


vii 


science  and  art  of  Paris  were  assembled  in  the  Palais  Mazarin.  Thou- 
sands, who  could  not  gain  admission,  besieged  the  doors.  The  busy 
newspapers  soon  spread  the  news  of  this  discovery  throughout  the  world, 
and  in  a  few  years  disciples  of  the  new  art  could  be  found  in  all  the  prin- 
cipal cities  of  Europe  and  America.  Morse,  the  celebrated  inventor  of 
the  well-known  telegraphic  apparatus,  was  the  first  who  introduced  the 
new  art  on  the  American  continent. 

Daguerre  accomplished  his  purpose  in  a  way  very  different  from  Niepce 
and  Wedgwood. 

He  employed  as  the  sensitive  substance  the  iodide  of  silver,  which  he 
produced  by  exposing  a  plate  of  silver  to  the  vapors  of  iodine.  The  light 
impression  which  such  a  plate  receives  in  the  camera  is  at  first  invisible, 
but  as  soon  as  the  plate  is  exposed  to  the  vapors  of  mercuiy  the  picture 
appears  with  all  its  details. 

This  is  a  cardinal  point  in  Daguerre 's  invention.  While  all  the  pre- 
ceding experimenters  tried  to  obtain  a  visible  picture  through  the  action 
of  light  only,  he  impressed  the  plate  with  a  latent  image,  which  only  be- 
came visible  by  a  secondary  operation, — the  development.  In  this  man- 
ner light  was  only  required  for  a  short  time  to  obtain  a  picture,  and  now 
it  became  possible  to  apply  photography  to  living  or  moving  objects. 

While  the  new  art — called  Daguerreotypy,  in  honor  of  its  inventor — 
held  its  triumphal  march  through  the  civilized  world,  there  lived  in 
England  a  rich  private  gentleman,  by  the  name  of  Fox  Talbot,  who 
pursued  the  same  object  as  Daguerre,  but  in  a  totally  different  manner. 
About  the  time  when  Daguerre  presented  his  first  picture  to  the  members 
of  the  Academy,  Talbot  made  a  communication  to  the  London  Royal 
Society  about  a  method  to  reproduce  pictures  by  the  aid  of  light.  Fol- 
lowing the  experiments  of  Wedgwood,  he  took  paper  impregnated  with 
common  salt,  and  allowed  it  to  float  on  a  solution  of  silver.  This  paper, 
containing  chloride  of  silver  and  the  nitrate  of  the  oxide  of  silver,  was 
placed  in  contact  with  a  copper-plate  engraving  and  exposed  to  sunlight ; 
it  proved  much  more  sensitive  than  that  employed  by  Wedgwood.  The 
light  penetrated  the  white  places  of  the  engraving  and  darkened  the  cor- 
responding parts  of  the  underlying  sheet.  A  white  picture  on  a  dark 
ground  was  the  result,  — a  negative. 

The  operation  was  then  repeated  ;  the  negative  took  the  place  of  the 
engraving,  a  piece  of  prepared  paper  was  placed  under  it,  and  by  expos- 
ing them  to  the  sunlight  a  fac  simile  of  the  original  print  was  produced. 
This  operation  can  be  repeated  at  pleasure,  and  thus  a  number  of  posi- 
tive copies  can  be  obtained  from  a  single  negative. 

By  this  invention  of  Talbot  photography  entered  the  ranks  of  the  re- 
producing arts. 

After  the  discovery  of  Daguerre  had  become  known,  Talbot  also  tried 
to  take  pictures  on  paper  by  means  of  the  camera.  He  floated  the  paper 
on  a  solution  of  iodide  of  potassa,  and  again  on  one  of  nitrate  of  silver  ; 
when  it  had  become  impregnated  with  iodide  and  nitrate  of  silver,  it  was 
exposed  in  the  camera.  In  this  manner  a  latent  picture  was  obtained 
in  a  short  time,  which  could  be  made  visible  by  employing  a  develop- 


viii 


INTRODUCTION. 


ment ;  for  this  purpose  Talbot  took  a  mixture  of  gallic  acid  aud  a  salt  of 
silver.  The  gallic  acid  reduces  the  salt  of  silver,  and  metallic  silver 
finely  divided  forms  a  black  precipitate,  covering  all  the  parts  which 
have  been  exposed  to  light.  A  negative  was  thus  obtained  from  which 
positives  could  be  made  in  the  manner  described  above.  This  process 
was  published  in  1841. 

Talbot's  pictures,  however,  compared  with  those  of  Daguerre,  were  so 
primitive  and  imperfect,  that  his  process  was  merely  considered  as  a 
curiosity,  and  attracted  little  attention.  The  rough  texture  of  the 
paper  was  fatal  to  the  delicacy  which  could  be  produced  on  the  polished 
and  mirror-like  plates  of  Daguerre. 

Soon,  however,  this  was  changed. 

Niepce  de  St.  Victor,  a  nephew  of  Nicephore  Niepce,  the  friend  of 
Daguerre,  following  the  example  of  Herschel,  substituted  for  the  paper, 
glass  plates,  and  made  them  the  bearers  of  the  sensitive  film  of  iodide  of 
silver.  He  coated  these  with  albumen  containing  iodide  of  potassium, 
immersed  them  in  a  silver  bath,  and  thus  obtained  a  very  sensitive  and 
homogeneous  film  on  which  he  could  take  pictures  much  more  delicate 
than  those  on  paper  ;  but  still  this  process  offered  great  difficulties. 

In  the  meantime  gun-cotton  was  discovered  by  Schoenbein  and  Boett- 
cher.  It  not  only  proved  itself  a  substitute  for  gunpowder,  but  was  also 
employed  in  the  healing  art.  It  was  found  that  this  substance  was  solu- 
ble in  a  mixture  of  alcohol  and  ether,  and  that  the  solution,  called  col- 
lodion, left  a  transparent  film  after  evaporation,  which  rendered  import- 
ant services  as  a  sticking-plaster. 

Legray,  in  1850,  was  the  first  who  tried  to  use  this  solution  of  gun- 
cotton  as  a  bearer  of  the  sensitive  salts  of  silver,  in  place  of  albumen, 
after  the  manner  of  Niepce,  but  did  not  succeed.  Archer  and  Fry,  in 
England,  were  more  fortunate.  Their  experiments  were  rewarded  with 
complete  success,  and  in  1851  Archer  published  a  complete  description 
of  his  new  collodion  process,  which  as  to  the  beauty  of  its  results  was  in 
•no  way  inferior  to  the  albumen  process  of  Niepce,  but  far  surpassed  it 
in  simplicity  and  certainty.  Archer  covered  plane  glasses  with  collo- 
dion containing  salts  of  iodine  in  solution,  immersed  them  in  a  silver 
bath,  and  thus  obtained  on  the  glass  a  delicate  film  saturated  with  sen- 
sitive iodide  of  silver.  This  plate,  when  used  in  the  same  manner  as 
Talbot's  paper,  gave  a  negative  of  extreme  sharpness  and  delicacy,  and 
excellent  positive  pictures  on  paper  could  be  produced  in  any  quantity 
desired  by  the  method  described  above.  The  discovery  of  Daguerre  was 
now  completely  superseded.  The  collodion  process  spread  rapidly,  and 
in  course  of  time  was  more  and  more  improved,  and  is  at  present  the  one 
exclusively  used. 

Its  rapid  introduction  is  due  partly  to  its  delicacy,  its  easy  execution, 
and  partly  to  the  advantage  that  the  collodion  pictures  can  be  multiplied 
in  a  much  simpler  manner  than  the  plates  of  Daguerre. 

These  circumstances  alone,  however,  would  not  have  been  sufficient  to 
give  it  the  precedence  over  the  process  of  Daguerre,  as  the  collodion 
plates  produce  at  first  only  a  negative  picture.    It  became  necessary, 


INTRODUCTION. 


ix 


therefore,  to  find  a  simple  and  easy  way  of  printing  positives  with  all 
the  details  contained  in  the  negative,  and  this  was  finally  reached 
through  a  special  preparation  of  the  Talbot  paper.  The  latter  was 
covered  with  albumen,  which  Niepce  had  already  successfully  employed 
in  the  preparation  of  negative  plates,  and  thus  the  albumen  paper  was 
made  a  medium  for  the  production  of  excellent  positives.  Collodion  for 
the  negative  and  albumen  paper  for  the  positive  process  form  now  the 
most  important  bases  of  our  photographic  pictures. 

Besides  these  successive  improvements  other  circumstances  contributed 
materially  to  the  rising  importance  of  photography. 

The  optical  apparatus  which  served  to  produce  the  pictures  in  the 
camera  were  improved.  Petzval  invented  the  double  objective  in  1841 , 
which  combines  extreme  intensit}-  of  light  with  correct  drawing. 

It  permitted  the  taking  of  objects  with  very  short  exposure,  and  now 
portraiture  was  brought  to  its  high  state  of  perfection. 

Simultaneously  with  this,  photographic  chemicals  were  produced  of 
great  purity  and  cheapness.  The  qualities  of  those  already  in  use  became 
better  known,  and  the  imperfect  ones  were  replaced  by  more  efficient 
ones. 

Fizeau,  Claudet,  and  Gaudin  discovered  the  greater  sensitiveness  of 
the  mixtures  of  iodide  and  bromide  of  silver.  Goddard  also  introduced 
mixtures  of  iodide  and  bromide  of  silver  into  the  collodion  process. 

Herschel  suggested  the  use  of  hyposulphite  of  soda,  which  removes  the 
sensitive  salts  of  silver  from  the  photographs,  and  thus  fixes  the  picture 
in  a  permanent  manner. 

Fizeau  introduced  the  gold  toning  bath,  which  removes  the  unpleas- 
ant color  and  makes  them  more  permanent. 

It  is  owing  to  these  and  other  numerous  discoveries  that  photographic 
operations  have  become  so  easy  and  practical,  that  any  moderately  skil- 
ful person  can  become  an  expert  in  a  short  time.  The  consequence  has 
been  that  an  immense  number  of  people  devoted  themselves  to  the  new 
art  in  the  expectation  of  making  money  rapidly  and  without  trouble. 

The  introduction  of  the  carte  de  visite  style  made  photography  popu- 
lar, and  the  public  rushed  to  the  galleries,  which  sprang  up  everywhere 
like  mushrooms.  In  the  same  manner  did  the  manufacture  of  photo- 
graphic apparatus  and  chemicals  gain  in  importance. 

Optical  establishments  were  started  for  the  exclusive  production  of 
photographic  lenses.  Cabinetmakers  devoted  their  whole  attention  to 
the  making  of  photographic  cameras,  picture  frames,  and  presses  ;  and 
other  accessories  required  special  factories  to  supply  the  growing  want. 
At  present  millions  enjoy  directly  and  indirectly  the  fruits  of  the  bene- 
ficial invention  of  Daguerre  and  Talbot. 

Many  of  their  followers  are  now  simultaneously  investigating  the 
hitherto  unexplained  physical  and  chemical  processes  of  this  art,  to  find 
new  branches  for  its  use,  and  to  do  away  with  the  imperfections  which 
still  exist.  Every  day  new  suggestions  are  made,  and  a  large  num- 
ber of  photographic  journals  are  published  to  register  the  new  discov- 
eries and  to  announce  them  to  the  world.    It  is  not  at  all  impossible 


X 


INTRODUCTION. 


that  a  new  and  more  perfect  process  may  supersede  that  of  Talbot  in  the 
same  manner  as  he  supplanted  Daguerre.  Quite  a  number  of  interest- 
ing experiments  have  already  been  made  .by  Niepce  de  St.  Victor,  Bec- 
querel,  and  Poitevin,  to  produce  photographs  in  their  natural  colors,  the 
fixing  of  which,  however,  has  not  yet  been  accomplished.  More  impor- 
tant and  successful  are  the  experiments  to  replace  the  expensive  salts  of 
silver  required  by  the  present  process  by  cheaper  materials. 

Herschel  employed  first  the  salts  of  iron,  Niepce  de  St.  Victor  and 
Burnett  the  salts  of  uran,  and  Mungo  Ponton  the  chroinates,  as  sensi- 
tive substances.  The  trials  hitherto  made  have  already  produced  re- 
markable results. 

Poitevin's  Carbon  Printing  Process  particularly  deserves  in  our  opin- 
ion the  greatest  consideration  of  all  the  recent  methods  of  printing.  It 
is  based  on  the  sensitiveness  of  chromate  of  potash. 

The  aim  is  now  to  increase  the  productiveness  of  photography  to  an 
unlimited  extent  by  combining  it  with  lithography  and  metal  plate  print- 
ing. Fizeau  was  the  first  who  tried  to  prepare  a  daguerreotype  plate 
with  acid,  and  thus  make  it  suitable  for  copper-plate  printing.  As  early 
as  1844  he  furnished  such  heliographs.  Fox  Talbot  succeeded  in  trans- 
ferring the  photographic  picture  on  steel,  and  made  a  photographic  steel- 
plate  engraving.  Poitevin  tried  to  produce  photolithographs,  a  process 
which  has  recently  been  highly  improved  by  Osborne,  Toovey,  James, 
Asser,  Lemercier,  Burchardt,  and  others.  The  problem  to  reproduce 
line  drawings  has  been  solved  and  is  already  generally  employed.  The 
rendering  of  the  half  tones,  however,  still  offers  difficulties.  These  were 
overcome  by  Albert's  new  discovery  of  a  process  similar  to  photolithog- 
raphy. Tessie  du  Mothay  tried  to  print  from  a  gelatin  film  in  the  man- 
ner indicated  by  Poitevin.  Albert,  in  Munich,  improved  this  method  to 
such  a  degree,  that  at  present,  under  the  name  of  the  Albert  or  "  Licht- 
druck  "  process,  it  is  practiced  in  numerous  establishments  of  Europe 
and  America.  In  a  still  more  perfect  manner  has  Woodbury  solved  the 
problem  to  make  photographs  in  the  printing  press.  He  furnishes  by  his 
relief-print  process,  not  only  the  most  excellent  pictures  on  paper,  but 
also  lantern  slides,  and  stereos  on  glass,  of  a  perfection  equal  to  those 
made  by  the  silver  process. 

Meanwhile  the  opticians  are  not  idle.  ISTew  instruments  by  Steinheil, 
Busch,  Ross,  Zentmayer,  and  Dallmeyer  increase  the  capabilities  of  pho- 
tography to  an  astonishing  degree.  In  like  manner  has  the  desire  to 
elevate  artistically  the  mechanical  productions  of  photography  given  an 
impetus  to  portrait  and  landscape  photography.  Legions  in  America, 
Adam-Salomon  in  Paris,  Robinson  in  London,  Loescher  &  Petsch  in 
Berlin,  have  set  a  noble  example,  and  artistic  elevation  of  photography, 
be  it  by  pose  and  lighting,  or  be  it  by  retouching,  has  become  the  watch- 
word of  all  photographers. 

In  this  Handbook  I  will  accordingly  devote  especial  attention  to 
artistic  photography. 

Dr.  H.  Vogel. 


CONTENTS. 


PAGE 

Introduction,  v 

PRACTICE  OF  PHOTOGRAPHY. 
CHAPTER  I. 

The  Arrangement  of  the  Gallery,     .       .       .       .       .       .       .  .17 

Size  of  the  Glass-house,  Size  of  the  Atelier,     ......  27 

Form  of  the  Gallery,  the  Glass-house  and  Accessory  Kooms,  .  .  .28 
Principles  of  Distribution  of  Light  in  the  Studio,  31 

CHAPTER  II. 
SECTION  I. 

The  Furnishing  of  the  Gallery,  40 

SECTION  II. 

The  Camera,  45 

SECTION  III. 

Use  and  Construction  of  the  Camera  Tube,  51 

CHAPTER  III. 

Description  of  Photographic  Objectives  (Tubes)  and  Lenses,  .       .  .54 

1.  Spherical  Aberration,  57 

2.  Chromatic  Aberration  or  Dispersion  of  Color,      .       .       .  .58 

Curve  of  the  Surface  of  the  Picture,  .59 

Distortion,  60 

Angle  of  View,  Actinic  Power,  and  Depth  of  Focus  of  a  Lens,  .  .  62 
Description  of  Photographic  Objectives,  .......  66 

1.  The  Simple  Achromatic  Objective,  or  the  so-called  Landscape 

Lens,    .   67 

2.  The  Portrait  Objective  68 

3.  The  Orthoscopic  Lens,  73 

4.  The  Triplet  Lens,  74 

5.  Steinheil's  Aplanatic  Lens,  75 

6.  The  Globe  Lens,  and  the  Pantoscope,  76 

On  Testing  Objectives,      ..........  79 

The  Stereoscope,   .83 

The  Panoramic  Apparatus,       .........  85 


xii 


CONTENTS. 


CHAPTER  IV. 

PAGE 

The  Negative  Process,   88 

SECTION  I. 

Preparation  of  the  Chemicals,        ........  88 

Kules  of  Precaution,   88 

1.  Preparation  of  the  Collodion,   90 

Pyroxylin,   90 

Iodizing  Salts,    ..........  94 

Action  of  the  Iodizing  Salts,     .......  98 

Preparation  of  Salted  Collodion,   102 

(a.)  Sodium  Collodion,  of  Dr.  Vogel,        ....  103 

(b.)  Equivalent  Collodion,  of  Dr.  Vogel,  .  104 

(c.)  Loescher  &  Petsch  Collodion,      .....  104 

(d.)  Kurtz  Collodion,  /  .  .104 

2.  The  Nitrate  of  Silver  Bath,   106 

3.  The  Developer,   107 

(a.)  Developer  for  Portraits  and  Landscapes,    ....  108 

(b.)  Developer  for  Reproducing  Line  Engravings,    .       .       .  108 

4.  The  Intensities   108 

5.  Fixing,   110 

6.  The  Varnish,   110 

7.  Glass  Plates,   Ill 

SECTION  II. 

Photographic  Operations,   113 

1.  The  Cleaning,   114 

Preliminary  Coating,         ........  116 

2.  The  Dusting,   117 

3.  The  Collodionizing,   117 

4.  The  Sensitizing,   119 

(a.)  The  Sensitizing  in  the  Bath,   120 

[b.)  The  Sensitizing  in  Dishes,   121 

5.  The  Exposure,      .       .       .   124 

6.  The  Development,   125 

7.  The  Intensification,   127 

8.  The  Fixing,   128 

9.  The  Intensifying  after  Fixing,   129 

10.  The  Varnishing,   129 


SUCCESSION  OF  THE  DIFFERENT  OPERATIONS  IN  THE  NEGATIVE 
AND  POSITIVE  PROCESSES. 

SECTION  I. 

The  Negative  Process,                                                                      .  131 

[a.)  Preparations,     ..........  131 

(b.)  Operations,        ..........  131 

SECTION  II. 

The  Care  of  the  Photographic  Apparatus  and  the  Chemicals,        .       .  132 

"            Photographic  Lenses,    .......  133 

»           Cameras,   133 

"            Glass  Plates,   134 

»           Collodion,   136 


CONTENTS.  Xlii 

PAGE 

The  Care  of  the  Silver  Bath,   138 

"           Developer,   142 

"            Intensifier,     .........  142 

"           Fixing  Bath,   142 

"            Varnish,   142 

»           Finished  Negative   143 

SECTION  III. 

Failures  in  the  Negative  Process,   143 

1.  Veils  or  Fog,   143 

2.  Failures  Due  to  the  Model,   144 

3.  "              Cleaning  and  Polishing  the  Plate,       .       .  144 

4.  "              Collodion,   145 

5.  "             Silver  Bath,   146 

6.  Failures  Due  to  Exposure,   147 

7.  "             Development,   147 

8.  Failures  in  Intensifying,   148 

9.  "        Fixing,   148 

10.  Failure  which  Manifests  Itself  on  Drying  the  Plate,  .       .       .  148 

11.  "     in  Varnishing,         ........  149 

NEGATIVE  RETOUCHING. 

SECTION  I. 

Practical  Part,   149 

SECTION  II. 

The  iEsthetical  Principles  of  the  Negative  Ketouch,     .       .              .  156 

CHAPTER  V. 

The  Positive  or  Silver  Printing  Process,   162 

SECTION  I. 

Preparations,   165 

I.  The  Paper,   165 

II.  The  Positive  Silver  Bath,   168 

III.  The  Toning  Bath,        .       .   170 

Normal  Gold  Solution,  and  the  Consumption  of  Gold,  ....  172 

1.  Alkaline  Gold  Toning  Baths,   173 

(a.)  Borax  and  Phosphate  of  Soda  Bath,   173 

(b.)  Chloride  of  Lime  Bath,   173 

2.  Neutral  Gold  Baths,   175 

(a.)  With  Chalk  (after  Davanne),   175 

(b.) |  "With  Carbonate  of  Soda,   175 

3.  Acid  Toning  Bath,   175 

Acetate  of  Soda  Bath,   175 

4.  Khodan  Gold  Bath,   176 

The  Fixing  Bath,   176 

Faults  of  the  Paper,   177 

SECTION  II. 

The  Practice  of  the  Silver  Printing  Process,   177 

Sensitizing  the  Paper,   178 

The  Printing,   180 

The  Printing  of  Vignettes,                                                       .  180 


xiv 


CONTENTS. 


PAGE 

The  Printing  of  Imperfect  Negatives,   181 

Printing  with  Several  Negatives  (Combination  Printing),     .       .  181 

Mezzotints  (Half-tone  Pictures),   182 

Oval  Pictures  (Medallions)  on  a  Gray  or  Black  Ground, .       .       .  182 

The  Watering,   183 

The  Toning,   183 

The  Fixing,   184 

The  Washing  after  Fixing,   184 

The  Finishing,   187 

SECTION  III. 

Gelatinizing  of  Photographs  and  Enamel  Pictures,       ....  189 

SECTION  IV. 

Care  of  the  Utensils  and  Chemicals  in  the  Positive  Process,  .       .       .  191 

Care  of  the  Negative,   191 

"          Paper,   194 

"          Positive  Silver  Bath,   195 

"          Sensitized  Paper,   200 

"          Toning  Bath,   201 

"          Fixing  Bath,   201 

SECTION  V. 

Failures  in  the  Positive  Process,   201 

1.  Failures  in  Silvering,  .       .       .       .   201 

2.  "        Printing,   202 

3.  "       Washing,   202 

4.  "        Toning,      .    202 

5.  »        Fixing,       .........  203 

6.  »        Washing  after  Fixing,   203 

7.  "        Finishing,   203 

SECTION  VI. 

The  Keduction  of  Silver  Kesidues,   203 

CHAPTER  VI. 

Different  Photographic  Processes,    .•   206 

SECTION  I. 

Permanent  Sensitive  Negative  Plates  (Dry  Plates),       ....  206 

Summary  and  Successive  Operations  in  the  Silver  Positive  Process,      .  206 

1.  Preparations,        ..........  206 

2.  Operations,   ...........  206 

The  Albumen  Dry  Process,   209 

1.  England's  Collodio-Albumen  Process,   209 

2.  The  Resin  Dry-Plate  Process  of  Harnecker,       ....  211 

3.  Russel's  Tannin  Process,   213 

4.  The  Bromo-Collodion  Process,     .......  213 

SECTION  II. 

Production  of  Transparent  Positives  and  Reproduction  of  Negatives,  .  221 

1.  Transparent  Positives  Produced  in  the  Camera,  ....  221 

2.  "               "            "          "     Printing-Frame,    .       .  224 

3.  Reproduction  of  Negatives,  ........  228 

(a.)  By  Means  of  the  Silver  Process,        .....  228 

(6.)          "          "     Dust  or  Powder  Process  of  Obernetter,  .  228 


CONTENTS.  XV 
SECTION  III. 

PAGE 

The  Transferring  of  Photographs  to  Other  Surfaces,      ....  232 

1.  Transferring  with  Ordinary  Collodion,   232 

SECTION  IV. 

Enlargements,   234 

1.  The  Indirect  Printing  Process,    .       .       .       .       .       .       .  235 

2.  The  Direct  Copying  Process,   235 

3.  Enlargement  by  Development,   236 

The  Carbon  Printing  Process,   237 

Pigment  Prints  on  Albumen  Paper,       .        .       ...       .       .        .  241 

The  Use  of  Dr.  Vogel's  Photometer,   242 

SECTION  V. 

Ferrotypes,   248 

CHAPTER  VII. 

Practical  Application  of  Photography,  .......  249 

SECTION  I. 

Photographic  Keproductions,   250 

Copying  of  Drawings,  Prints,  Oil  Paintings,  etc.,  etc.,   250 

1.  Preparation  of  the  Original,   250 

2.  Arrangement,       ..........  250 

3.  Illumination,        ..........  252 

4.  The  Lens,   253 

5.  Protection  of  the  Objective  against  Foreign  Light,     .       .       .  253 

6.  Time  of  Exposure,   254 

7.  Methods  of  Operation — Formulae,   255 

8.  The  Printing,   256 

9.  Criticism  of  the  Result,   257 

SECTION  II. 

The  "  Lichtpaus  "  Process,   258 

SECTION  III. 

Photographing  of  Models,  Ornaments,  Statues,  Works  of  Art,  Machi- 
nery, etc.,   260 

1.  Preparation  of  the  Object,'  and  Arrangement,     ....  260 

2.  Illumination  and  Exposure,   262 

3.  Lenses,   263 

SECTION  IV. 

Stereoscopic  Pictures,   264 

Instantaneous  Pictures,   269 

Tent  Work  and  Photographic  Excursions,   270 

(a.)  For  Short  Excursions,   274 

SECTION  V. 

Architecture  and  Interiors,   278 

SECTION  VI. 

Microphotography,  ...........  278 


xvi 


CONTENTS. 


SECTION  VII. 

PAGE 

Spectral  Photography,   282 

SECTION  VIII. 

Astronomical  Photography,   284 

1.  Objective,   285 

2.  Tube  and  Focus,   285 

3.  Camera,   .       .  *    .  .286 

1.  Adjusting  the  Objective,   287 

2.  Adjustment  of  the  Plate,   287 

3.  Adjustment  of  the  Enlarging  Objective,      ....  287 

First  Method,   287 

Second  Method,   288 

The  Art  of  Photography,  or  Photographic  ^Esthetics,  ....  292 

Photography  and  Truth,   293 

On  Light  and  Illumination,    .........  300 

Of  the-  Perspective,   313 

Distortion,       .       .   321 

Arrangement  of  the  Picture,  .........  330 

Lines  and  Outlines,  ...........  342 

Dress  and  Draperies,       ......       ....  346 

Position  and  Standpoint,  ..........  353 

(a.)  The  Arrangement  of  Human  Figures,      .....  853 

(b.)  Arrangements  in  Landscapes  and  Architecture,       .       .       .  357 

Characteristics  and  Individuality,   360 

The  Treatment  of  the  Public,   370 

Filling  the  Picture,   374 

Accessories  and  Backgrounds,   374 

Supplement,     ............  384 

Weights  in  Photography,   384 


THE 


PRACTICE  OF  PHOTOGRAPHY. 


CHAPTEE  I. 

THE  ARRANGEMENT  OF  THE  GALLERY. 

The  photographer,  like  every  other  artist  or  mechanic,  requires  for 
his  labors  a  place  where  he  is  protected  against  the  influences  of  the 
weather. 

These  labors  are  of  various  kinds, — partly  mechanical,  as  the  cut- 
ting and  cleaning  of  plates ;  partly  chemical,  as  the  preparation  of 
collodion,  silvering  of  paper,  developing,  intensifying,  fixing,  and 
washing ;  partly  physical  and  optical,  as  the  focussing  and  exposing ; 
and,  finally,  partly  artistic,  as  the  posing  of  the  sitter,  the  arrange- 
ment of  the  drapery,  the  illumination,  and  the  negative  and  positive 
retouching.  It  is  evident  that  these  operations  cannot  all  be  carried 
on  in  the  same  room,  particularly  as  some  of  them  demand  diametri- 
cally opposite  conditions  for  their  success.  The  taking  of  the  model 
requires  much  light,  while  the  preparation  of  the  plates  must  be 
carried  on  in  almost  total  darkness. 

Every  photographer  needs,  therefore,  a  suite  of  rooms,  which,  how- 
ever, frequently  appear  reduced  to  two, — the  studio  and  the, dark-room. 

In  assigning  proper  localities  to  the  different  work  to  be  performed, 
particular  attention  should  be  paid  to  separating  those  branches  which 
are  in  their  nature  antagonistic. 

The  silver  bath  should  not  be  evaporated  in  a  room  where  prints 
are  being  mounted.  The  plate  while  being  fixed  must  not  be  exposed 
to  the  danger  of  being  sprinkled  with  the  developer,  not  to  mention  a 
hundred  other  precautions. 

The  necessity  for  a  division  of  labor  and  space  increases  with  the 
magnitude  of  the  establishment,  in  order  that  each  particular  kind  of 
work  may  be  carried  on  independently. 

2 


18 


THE  PRACTICE  OF  PHOTOGRAPHY. 


A  drawback  to  the  proper  arrangement  of  photographic  ateliers  is 
generally  met  with  in  the  fact  that  they  are  located  in  the  upper  stories 
of  houses  which  were  originally  designed  for  other  purposes.  The 
consequence  is  that  they  must  accommodate  themselves  to  the  already 
existing  proportions,  and  this  can  only  be  done  by  sacrificing  many 
advantages. 

We  find,  therefore,  the  greatest  diversity  in  the  arrangement  of  pho- 
tographic galleries.  Only  one  principle  in  the  above-stated  necessity 
of  a  division  of  labor  seems  to  be  persistently  carried  out,  namely,  the 
separation  of  the  negative  and  positive  processes. 

As  examples  of  the  arrangement  of  a  gallery,  we  will  give  two 
practical  illustrations.  The  one  is  the  photographic  atelier  of  the 
Eoyal  Academy  of  Technology,  the  other  the  atelier  of  Loescher  & 
Petsch,  at  Berlin.  Any-  one  who  desires  to  arrange  an  establishment 
will  find  in  these  descriptions  a  guide,  although  local  conditions  will 
often  compel  a  modification  of  these  plans. 

The  atelier  of  Loescher  &  Petsch  has  this  great  advantage,  that  it 
has  been  erected  exclusively  for  photographic  purposes,  which  have, 
however,  had  portrait  photography  solely  in  view,  while  the  atelier  of 

Fig.  1. 


^fffffffTff 


the  Koyal  Academy  of  Technology  is  devoted  more  to  technical  pur- 
poses, such  as  the  copying  of  drawings,  machinery,  etc. 

The  photographic  atelier  at  the  Academy  (Fig.  1)  consists  of  a  glass- 


THE  ARRANGEMENT  OF  THE  GALLERY. 


19 


house,  A,  32  feet  long  by  22  feet  in  width.  The  height  of  the  front 
glass  wall  or  sash  is  10  feet  6  inches ;  the  rear  wall  is  16  feet  high. 

The  roof  is  only  glazed  for  a  distance  of  16  feet.  The  atelier  itself 
does  not  face  exactly  north,  but  north-northwest,  conforming  to  the 
building  on  which  it  is  erected.  In  the  summer-time  the  afternoon 
sun  shines  on  the  glass-house,  an  evil  which  can  only  be  partially 
remedied  by  awnings  and  curtains. 

The  curtains  are  arranged  according  to  the  old  system  of  Loescher 
&  Petsch,  which  appears  the  most  rational,  and  has  already  been 
adopted  by  several  Berlin  photographers.  It  consists  of  side  curtains 
which  can  be  moved  in  a  vertical  direction,  and  top-light  curtains 
which  move  parallel  to  the  inclination  of  the  roof.  A  section  of  the 
side  curtain  is  represented  in  Fig.  2,  and  Fig.  3  represents  one  of  the 
top-light  curtains  with  the  cords  for  moving  it. 


Fig.  2. 


The  curtains  are  2  feet  wide  and  overlap  each  other  like  the  shingles 
of  a  roof,  in  order  to  exclude  the  light  completely  (see  Fig.  2).  The 
guides  are  thin  wires,  d,  on  which  the  iron  rods,  E,  which  carry  the 
curtains,  slide. 


20 


THE   PRACTICE  OF  PHOTOGRAPHY. 


It  is  easy  to  darken  the  whole  atelier,  to  make  openings  of  2,  4,  or 
6  feet  in  width,  and  of  any  suitable  length,  and  to  modify  the  direc- 
tion of  the  entering  rays  in  various  ways. 

The  cords  for  the  side  curtains  pass  over  the  rollers  r,  r,  r,  r,  which 
are  fastened  near  the  roof  to  the  board  My  and  at  the  floor  to  L;  the 
cords  can  be  tightened  by  the  screws,  g,  g.  The  wires  d,  dy  of  the  side 
curtains,  hang  down  loosely,  while  those  of  the  roof  admit  of  tighten- 
ing by  the  screws  q,  q  (see  Fig.  3).  The  cords  of  the  top  curtains 
pass  through  porcelain  rings*  ls  ly  which  are  fastened  to  M  and  L> 


Fig. 3. 


The  curtains  are  made  of  very  opaque  double  blue  material. 

The  above  system  was  especially  designed  for  portraiture,  which, 
however,  is  not  the  class  of  work  done  at  the  Academy ;  still  it  does 
excellent  service  in  the  taking  of  plastic  objects. 

Immediately  adjoining  the  glass-house,  and  on  the  same  floor  with 
it,  is  the  printing-room,  K  (see  Fig.  1),  with  a  window  facing  north- 
northwest,  and  a  top-light  one-half  the  size  of  that  which  covers  the 
atelier.    A  sliding  door  leads  to  the  latter,  which  is  opened  when  it 


THE   ARRANGEMENT  OF  THE  GALLERY. 


21 


becomes  necessary  to  remove  the  camera  to  a  great  distance  from  the 
object  to  be  taken  ;  by  this  arrangement  the  apparatus  can  be  removed 
45  feet  from  the  opposite  wall  of  the  glass-house. 

The  width  of  the  printing-room  is  only  14  feet ;  the  length  and 
height  are  those  of  the  atelier.  The  top-light  is,  for  printing  pur- 
poses, a  little  too  high.  In  order  to  bring  the  frames  nearer  to  the 
light  a  movable  platform  of  wood  has  been  constructed,  which  by 
mechanical  means  can  be  elevated  to  a  height  of  8  feet,  or  lowered  at 
pleasure. 

The  printing-room  is  divided  in  two  parts.  The  back  part,  E,  serves 
as  a  dark-room,  where  the  papers  are  placed  in  the  frames,  and  where 
the  progress  of  printing  is  examined.  The  fresh  copies  are  also  kept 
in  this  room.  The  front  part  serves  for  exposure.  A  side  door,  t, 
leads  to  the  roof,  where,  when  necessary,  the  work  can  be  carried  on 
in  the  open  air. 

Immediately  adjoining  the  printing-room,  but  a  little  higher  situated 
than  the  latter,  and  connected  with  it  by  a  staircase,  are  the  rooms  for 
the  further  manipulation  of  the  paper  prints.  1st.  The  wash-room,  V. 
2d.  The  finishing-room,  B.  The  former  contains  two  troughs  lined 
with  asphaltum.  They  are  5  feet  long  by  feet  wide.  They  rest  on 
the  tubs,  T.  One  of  these  troughs  is  for  washing  the  fresh  copies ;  the 
other  for  washing  the  fixed  prints.  An  opening  carries  the  wash- 
water  with  the  silver  contained  in  solution  into  the  tub,  T.  Another 
opening,  which  can  be  closed,  leads  the  waste  water  into  the  street. 

The  tub  T  receives  the  water  containing  soda,  and  T'  the  solutions 
which  are  free  from  this  substance. 

The  tables,  S,  S,  are  for  silvering  paper ;  the  toning  is  done  in  the 
light  part  of  the  printing-room. 

The  adjoining  space,  B,  is  used  for  mounting,  retouching,  and  rolling 
the  pictures,  and  also  serves  as  a  store-room  for  paper,  chemicals,  etc. 

We  now  proceed  to  describe  the  apartments  devoted  to  the  negative 
processes.  Here  we  have,  first,  a  small  laboratory  with  top-light,  L, 
in  which  the  chemicals  are  mixed,  the  baths  and  other  substances 
tested.  Evaporations,  and  all  other  chemical  processes,  are  also  carried 
on  here. 

In  the  room  next  to  the  furnace  are  two  places  for  evaporation,  G, 
G;  the  one  for  liquids  containing  silver  in  solution,  the  other  for  the 
solutions  containing  chlorine  (gold  solutions,  etc). 

The  reduction  of  the  silver  residues  of  the  different  melting  pro- 
cesses is  finally  done  in  the  large  laboratory  of  the  Institution. 

D,  D,  is  the  dark-room  for  the  preparation  of  the  plates.    By  a 


22 


THE  PRACTICE  OF  PHOTOGRAPHY. 


curtain,  M,  it  is  divided  in  two  parts,  and  a  space,  T,  T,  is  partitioned 
off  in  the  centre  for  the  preparation  of  dry  plates. 

In  D'  the  plates  are  cleaned,  and  all  the  work  connected  with  clean- 
ing is  done  here. 

C,  C,  is  the  table  with  the  silver  bath ;  H  the  developing,  and  H' 
the  fixing  trough.  They  are  separated  by  a  partition,  and  each  trough 
consists  of  two  parts.  From  the  left  part  the  rinsing  waters,  which 
are  rich  in  silver,  are  carried  in  a  tub  underneath  the  table ;  the  right- 
hand  part  serves  for  the  final  washing,  and  the  waste  water  is  carried 
off  into  the  gutter.  The  width  of  each  of  the  four  troughs,  which  are 
lined  with  asphaltum,  is  2^  feet.  Gas  and  water-pipes  run  of  course 
through  the  whole  establishment. 

At  P  are  shelves  for  plates. 

The  dark-room  communicates  with  the  atelier  by  the  entry,  0,  0. 

Perhaps  it  would  have  been  better  if  the  laboratory,  L,  had  been 
taken  for  the  dark-room,  but  the  arrangement  of  the  building  would 
not  permit  it,  and  the  peculiar  construction  of  the  basis  on  which  the 
atelier  was  constructed  caused  unusual  difficulties  in  the  proper  dis- 
tribution of  the  different  localities.* 

The  knowledge  of  several  deficiencies  in  the  construction  of  the 
studio  of  Messrs.  Loescher  &  Petsch,  which,  in  the  course  of  time, 
became  more  and  more  annoying,  and  gave  rise  to  an  unpleasant 
feeling  of  being  dependent  on  the  peculiarities  of  the  atelier,  induced 
these  gentlemen  to  embody  their  experience  in  a  new  building,  which 
should  be,  as  near  as  possible,  perfection. 

The  principal  ideas  which  guided  them  in  the  execution  of  this 
work  were,  that  the  photographer,  by  the  nature  of  his  art,  is  com- 
pelled to  make  the  most  of  the  few  moments  of  exposure,  to  take  into 
account  every,  even  the  smallest  advantage  in  regard  to  illumination, 
the  management  of  the  decorative  or  technical  accessories  and  utensils, 
and,  finally,  to  avoid  everything  which  can  give  trouble  or  become  a 
hindrance.  This  is  the  only  way  to  enable  him  to  devote  his  whole 
and  undivided  attention  to  the  person  whose  picture  he  is  to  take, 
and  to  the  arrangement  and  the  harmonizing  of  the  principal  effects. 
Another  important  point  is  the  location  of  the  studio.  It  should  be 
located  on  the  ground-floor ;  for,  besides  this  being  the  most  conve- 
nient for  the  public,  such  a  location  admits  also  the  total  exclusion  of 
direct  sunlight,  by  placing  it  to  the  north  of  a  tall  building.  Atten- 
tion should  also  be  paid  to  a  proper  arrangement  of  the  different 

*  It  will  be  noticed  in  Fig.  1  that  the  various  rooms  are  not  on  the  same 
level,  and  communicate  by  steps  with  one  another. 


THE  ARRANGEMENT  OF  THE  GALLERY.  23 

work-rooms,  partly  to  save  time,  partly  to  enable  the  head  of  the 
establishment  to  have  every  department  constantly  under  his  eye. 
These  were  the  general  principles  which  Messrs.  Loescher  &  Petsch 
tried  to  embody  in  their  new  establishment.  How  difficult  it  is  to 
find  a  locality  where  all  these  advantages  are  combined,  anybody 
who  is  acquainted  with  Berlin  will  know. 

The  building  is  located  in  a  garden.  No  trees  or  shrubbery  can 
have  an  injurious  effect  on  the  light,  as  for  a  distance  of  one  hundred 
and  fifty  feet  the  space  is  perfectly  clear. 

The  annexed  ground-plan  will  explain  how  the  different  rooms  are 
connected  together.  The  advantages  of  this  arrangement  are,  prin- 
cipally, that  the  photographer  is  enabled,  at  any  leisure  moment,  to 
communicate  with  the  counting-room,  the  mounting-room,  the  retouch- 
ing-room, or  the  printing  establishment.  He  can  constantly  overlook 
and  superintend  the  working  of  all  the  different  departments. 


Fig.  4. 


GROUND-PLAN  OF  THE  BUILDING, 

A,  studio  ;  C,  counting-house ;  WZ,  waiting-room  ;  B,  mounting-room  ;  PR,  artist's  studio  for 
coloring ;  P,  vestibule ;  B,  balcony ;  DK,  dark-room ;  NR,  room  for  negative  retouching,  under- 
neath -which  are  the  wash-room  and  copying- room ;  T,  staircase  leading  to  the  printing-room. 

The  main  glass-room  faces  nearly  due  north,  and  is  protected  by 
the  two-story  house  from  the  direct  rays  of  the  sun.  The  printing- 
room,  the  main  side  of  which  also  points  north,  is  likewise  protected 
against  direct  sunlight. 

The  studio  proper  is  of  the  following  dimensions:  35  by  17  feet 
floor,  and  height  from  10  to  14  feet.  The  inclination  of  the  roof  is 
4  feet  in  17,  and  is  sufficient  to  remove  the  accumulated  dirt  when- 
ever a  rainfall  occurs.  The  moisture  on  the  inside,  caused  by  con- 
densed vapor,  runs  off  through  a  small  slit  between  the  roof  and  the 
sides.  In  this  way  the  gutters,  which  are  generally  placed  below  the 
supports,  could  be  dispensed  with.    At  the  junction  of  the  two  glass 


24 


THE  PRACTICE  OF  PHOTOGRAPHY. 


surfaces  is  a  slight  iron  rod  to  carry  the  rollers  for  the  illuminating 
apparatus,  which  absorb  very  little  light.  The  northern  side  and 
about  three-fourths  of  the  roof  are  glazed.  The  plates  of  glass  are  24 
inches  square,  and  only  16  bars  were  necessary  as  supports.  The 
central  ones  are  fth  in.  by  3  inches  ;  the  side  ones  are  an  inch  thinner. 
In  this  way  a  broad  mass  of  light  from  the  north  became  available, 
which,  in  some  particular  instances  only,  had  to  be  modified.  It 
became  necessary  to  invent  an  arrangement  which  would  exclude 
every  particle  of  side-light,  and  reduce  the  source  of  light  to  one  open- 
ing only.  Ease  in  the  management  and  certainty  in  the  effect  were 
necessary,  durability  and  a  pleasing  appearance  desirable.  These 
considerations  induced  Mr.  Petsch  to  substitute  for  the  old-fashioned 
curtains  of  doubled  muslin,  frames  covered  with  some  opaque  material, 
which  were  easily  movable  and  avoided  all  the  shortcomings  of  the 
former  arrangement.  The  old  arrangement  with  curtains  never  ex- 
cluded the  light  absolutely,  while,  at  the  same  time,  they  would,  in 
course  of  time,  hang  down  loosely,  leaving  openings  between  the  dif- 
ferent strips,  the  light  from  which  would  be  annoying  to  the  sitter 
and  interfere  with  a  proper  illumination,  not  to  speak  of  the  dust  and 
unsightly  appearance. 

With  the  frame  arrangement  the  supports  for  the  glass  became 
available  as  carriers  for  the  frames,  doing  away  with  all  the  rods, 
wires,  rings,  and  cords  of  the  old  establishment.  The  frames  are 
made  of  light  iron  bands,  covered  with  linen  which  is  made  water- 
and  light-tight  by  a  coating  of  glue,  chalk,  and  oil  paint. 

To  the  supports  of  the  roof,  corner-irons  e  (Fig.  5)  f  in.  by  f  in.  are 
riveted,  and  these  carry  the  frames.  The  irons  have  three  grooves, 
in  each  of  which  a  frame  can  be  moved  without  touching  the  other 
one.  Placed  side  by  side,  they  cover  the  glazed  three-quarters  of  the 
roof  completely ;  placed  one  above  the  other,  and  pushed  under  the 
covered  quarter  of  the  roof,  the  glazed  part  is  unobstructed.  See  the 
two  cuts  below : 


Fig.  5.  Fig.  6. 


t 


Fig.  7  will  show  this  arrangement — cross  section. 

H  is  the  rear  wall ;  h  a  wooden  covering  for  the  roof ;  r,  /,  r"r,  are 
the  frames  which  move  in  the  guides  as  shown  in  the  figures  above. 
Each  frame  has  two  small  hooks,  xf,  x" ' ,  x"'7  etc.    The  frames  are 


THE  ARRANGEMENT   OF  THE  GALLERY. 


25 


moved  by  cords,  which  at  H  and  V  pass  over  rollers,  and  which  at 
V  are  fastened  to  the  first  frame.  In  admitting  light,  r'  will  move 
backwards,  first  the  hook  x'  will  catch  the  corresponding  hook  x"  of 
frame  /,  and  take  the  second  frame  along,  and  so  all  the  frames  will 
be  caught  in  succession.  Friction  is  partially  overcome  by  strips  of 
wood,  h,  Fig.  5,  which  are  covered  with  plumbago,  and  placed  under 
the  frames ;  so  also  are  the  hooks  F,  Fig.  5,  covered  with  felt  to  avoid 
jarring. 

The  movement  of  the  frames  is  easy  and  certain,  and  the  exclusion 
of  the  light  complete. 

Fig.  7. 


The  side-light  is  regulated  in  a  similar  manner.  Instead  of  three 
frames,  two  only  are  needed.  They  run  in  a  wTide  groove,  and  can 
be  pushed  partially  below  the  floor  of  the  studio. 

The  distribution  and  character  of  the  backgrounds  and  furniture 
were  made  with  due  regard  to  the  tendencies  of  the  times,  which,  in 
costume  and  everything  else,  incline  to  the  Kococo  and  Kenaissance 
styles.  With  this  end  in  view,  one  side  of  the  studio  is  provided 
with  furniture  and  drapery  of  the  former  style,  and  the  other  side 
with  accessories  corresponding  with  the  latter  taste. 

The  old  and  practical  way  of  moving  the  backgrounds  on  rollers 
and  horizontal  rails  has  not  been  changed,  excepting  an  arrangement 
by  which  the  background  can  be  placed  obliquely  to  the  light.  The 
light  and  shade  effects  are  partially  regulated  by  screens  and  re- 
flectors. The  color  of  the  furniture  is  a  mixture  of  burnt  umber  and 
chalk,  not  so  dark  that  black  cloth  will  not  show  upon  it. 

The  size  of  the  background  is  7  feet  wide  and  8  feet  high,  and  as 
the  studio  is  17  feet  wide,  two  backgrounds  can  be  placed  side  by  side. 

In  the  room  for  negative  retouching,  which  adjoins  the  studio,  there 
are  three  desks  side  by  side.  Each  desk  has  a  ground-glass  window 
H  feet  square ;  the  front  part  of  the  desk  can  be  raised  or  lowered 
so  as  to  admit  of  moving  the  easel  nearer  to  or  further  from  the 
window.  At  night  a  lamp  is  used.  The  lamps  are  provided  with 
Argand  burners,  and  parabolic  reflectors  of  polished  metal.  The 


26 


THE  PRACTICE  OF  PHOTOGRAPHY. 


back  part  of  the  reflector  being  cut  away,  the  direct  light  passes 
through,  while,  at  the  same  time,  the  side  rays  also  are  thrown  on  the 
negative. 

The  other  localities  are  not  much  different  from  those  of  similar 
establishments.  A  room  facing  south,  underneath  the  studio,  is  used 
for  printing,  toning,  and  washing  the  prints.  In  this  room  the  paper 
is  also  sensitized. 

In  the  reception-rooms,  the  aim  has  been  rather  to  please  by  a  tasty 
simplicity  than  to  dazzle  the  eye  with  gaudy  splendor. 

The  dark-room,  as  well  as  several  other  localities,  are  heated  with 
hot  air.  Above  the  flue  in  the  dark-room,  is  a  wire  arrangement,  on 
which  the  negatives  are  placed  to  facilitate  their  drying. 

The  arrangement  for  washing  the  pictures  consists  of  two  large  tin 
boxes.  The  water  is  introduced  through  many  small  holes,  and  when 
it  has  reached  a  certain  height,  two  siphons  empty  the  boxes,  and  the 
process  begins  anew. 

Finally,  it  may  not  be  amiss  to  say  that  it  is  not  claimed  that  the 
above  arrangements  are  perfect,  but  the  aim  has  been  to  go  a  step 
forward  in  the  construction  of  a  first-class  studio. 

Large  Berlin  galleries  have  frequently  the  printing-room  over  the 
gallery.  (See  the  exterior  of  Milster's  atelier,  Fig.  10.) 

For  smaller  establishments,  suitable  for  provincial  towns,  we  recom- 
mend the  following : 

The  glass-house  I,  I,  I',  V,  and  the  printing-house  k,  I',  I,  are  placed 
on  the  same  floor ;  next  comes  the  negative  dark-room  ND,  3|  metres 
long,  2.5-3.5  metres  wide,  and  the  positive  dark-room  PD.  The 
glass-house  should  be  7.84  metres  (25  feet)  long,  and  4  metres  (12 J 

feet)  wide ;  the  depth  of  the  glass  roof 
2.5-2.8  metres  (8-9  feet),  and  its  pitch 
0.8  metres  (2 J  feet).    The  glass  side 
V,  I',  faces  north.    The  printing-room 
px  should  be      metres  (8  feet)  wide,  and 
the  glass  roof  as  above ;  the  door  a,  b, 
1.25  metres  (4  feet)  wide,  is  in  the 
middle  in  order  to  move  the  camera  as 
far  back  as  possible  when  we  want  to 
make  whole-length  portraits  on  plates 
7"  x  9".    When  we  wish  to  be  saving,  the  dotted  parts  Ip,  Ip  =  62 
centimetres  (2  feet)  wide,  may  be  left  unglazed. 

For  the  curtain  arrangement  for  these  small  galleries,  we  recom- 
mend Schaarwachter's  plan  (Fig.  9).    It  consists  of  three  hanging 


Fig.  8. 
if  J/orCK, 


JTD 


SIZE  OF  THE  ATELIER. 


27 


curtains  for  the  glass  side  r,  s,  t,  which  run  on  a  single  stretched  brass 
wire  d,  d. 

Such  brass  wires,  six  in  number,  are  stretched  along  the  glass  roof ; 
each  two  of  these  wires  carry  three  curtains,  o,  p,  q.  Cords,  rings  and 
rollers  do  not  exist.  With  the  aid  of  a  long  stick  the  roof  curtains 
o,p,  q,  may  be  separated,  in  such  a  manner  that  they  cover  it  entirely, 
or  they  may  .be  pushed  together  and  openings  of  any  desired  size  can 
be  made.    The  like  may  be  done  with  the  curtains  of  the  glass  side 

Fig.  9. 


1  2        P       3  4 


r,  s,  t.  When  we  wish  to  exclude  the  light  from  the  feet  of  the  sitter, 
the  lower  part  of  the  glass  side  is  covered  up,  by  fastening  the  ends  of 
s  and  t  together. 

For  short  exposure  the  parts  1,  2,  3,  of  the  side  and  roof  are  opened, 
and  4  remains  closed.  For  good  light,  longer  exposure  and  artistical 
illumination,  section  3  of  the  side  and  3  C  of  the  roof  are  opened ; 
with  feeble  light  we  also  open  2  of  the  side  and  the  section  1  A,  B, 
and  C;  of  course  a  few  inches  more  or  less  make  no  difference.  We 
can  of  course  only  give  sketches  here  which  the  thoughtful  artist  may 
modify  at  pleasure. 

SIZE  OF  THE  ATELIER. 

What  dimensions  shall  we  give  the  atelier  ? 

We  have  to  consider,  first,  another  point, — i.  e.,  distance. 


28 


THE   PRACTICE   OF  PHOTOGRAPHY. 


We  need,  for  a  picture  of  carte  de  visite,  or  for  one  of  half  size, 
lenses  of  different  focal  length,  and  also  a  different  distance  from  the 
apparatus  to  the  object.  The  longer  the  focal  length  of  an  objective, 
the  greater  must  be  the  distance  between  the  model  and  the  camera. 
In  a  tunnel  atelier  this  can  be  accomplished  by  extending  the  tunnel. 
In  a  north  front  atelier,  where  the  apparatus  stands  in  the  glass-house, 
it  is  necessary  that  this  should  have  the  proper  length,  provided  that 
we  cannot  remove  the  apparatus  into  an  adjoining  apartment. 

The  length  of  a  glass-house,  where  no  adjoining  rooms  are  at  the 
disposal  of  the  operator,  should  not  be  less  than  20  feet. 

The  smallest  width,  when  we  do  not  wish  to  be  cramped  in  our 
operations,  should  be  10  feet.  In  such  a  room  standing  figures,  for 
which  the  greatest  distance  is  necessary,  could  be  taken  only  of  card 
size.  For  standing  figures  of  larger  size  such  an  atelier  would  not  be 
sufficient.  For  such  figures  in  cabinet  size  at  least  24  feet  would  be 
necessary,  and  for  8  J  by      plates  at  least  30  feet  would  be  required. 

For  busts,  etc.,  a  shorter  distance  would  suffice. 

Groups,  which  besides  the  height  extend  in  breadth,  require  still 
larger  distances  than  standing  figures,  and  want  besides  a  correspond- 
ing width.  An  atelier  40  feet  long  and  20  feet  wide  would,  however, 
answer  almost  all  requirements.  The  height  of  the  glass  side  we  would 
recommend  should  not  exceed  10  feet  (Adam  Salomon,  whose  light- 
effects  are  so  much  praised,  has  an  atelier  8  feet  high).  The  glass  roof 
must  ascend  to  the  rear,  like  a  desk,  in  order  to  shed  the  rain-water. 
I  would  recommend  for  a  distance  of  10  feet  an  ascent  of  2  feet.  The 
depth  of  the  glass  roof  itself  should  be  nearly  equal  to  the  depth  of 
the  atelier.  The  lighting  of  the  shadows  will  thus  be  under  perfect 
control  by  opening  more  or  less  the  top  curtains. 

FORM  OF  THE  GALLERY,  THE  GLASS-HOUSE,  AND  ACCESSORY  ROOMS. 

Fig.  10  gives  the  outside  view  of  Milster's  atelier  in  Berlin.  It  is 
32  feet  in  length  and  23  feet  in  width.  Above,  the  iron  rods  are  visi- 
ble on  which  the  awniug  for  protection  from  the  sun,  is  fastened. 

In  winter-time  these  awnings  are  unnecessary;  not  so  in  summer, 
when  the  sun,  here  in  Berlin,  reaches  an  altitude  of  over  70°.  The 
great  objection  to  awnings  is  that  they  very  easily  tear.  Every  storm 
of  wind  endangers  them,  besides  they  do  not  ornament  the  building. 
A  more  solid  arrangement  the  author  noticed  in  America,  and  it  was 
described  on  page  20,  vol.  i,  Photographic  World.  It  consists  of  a  suc- 
cession of  screens,  i.  e.,  boards  of  any  desired  width,  and  of  a  length 
equal  to  that  of  the  gallery ;  these  are  placed  parallel  to  the  gallery. 


FORM  OF  THE  GALLERY. 


29 


Each  board  can  be  turned  around  its  axis,  which  rests  on  an  iron 
support.  If  the  gallery  is  longer  than  20  feet,  a  central  support  will 
be  necessary.  On  every  axis  of  the  boards  is  a  crank  connected  with 
a  rod.    This  rod  can  be  fastened  to  the  iron  work  in  any  position. 


Fig.  10. 


This  arrangement  admits  of  placing  the  boards  in  any  inclination 
that  is  desired.  On  the  21st  of  June,  when  the  sun  has  an  altitude 
of  74°,  the  position  of  the  boards  would  be  almost  flat.  On  other 
days,  when  the  altitude  is  less,  they  are  opened  wider;  in  winter- 
time they  may  be  placed  vertically  except  in  a  snow  or  hail  storm, 
when  they  are  closed  altogether  to  protect  the  glass.  It  is  to  be 
remarked  that  this  arrangement  excludes  the  sun's  rays  only  when 
the  sun  is  not  too  far  east  or  west. 

In  summer-time,  when  the  sun  even  goes  northward,  a  side  protec- 
tion is  needed  for  the  western  side.  For  this  purpose  an  awning  is 
preferable.  To  those  who  do  not  wish  to  employ  this  arrangement, 
we  recommend  to  paste  over  the  glass  silk  paper,  or  covering  it 
with  a  thick  starch  paste.  In  winter-time,  when  top-light  is  more 
necessary,  the  starch  film  is  removed  with  hot  water.  Other  photog- 
raphers employ  white  muslin  curtains  to  dampen  the  top-light,  and 
also  dark-blue  ones  for  the  total  exclusion  of  light.    Still  others  em- 


30 


THE  PRACTICE  OF  PHOTOGRAPHY. 


ploy  ground-glass.  The  corrugated  glass  has  proven  very  successful ; 
it  permits  almost  as  much  light  to  pass  through  as  the  plain  glass, 
but  disperses  it  so  much  that  it  does  not  dazzle  any  longer.  The 
glass  with  cylindrical  ridges  should  not  be  selected,  but  rather  a  glass 
in  which  the  knobs  are  very  close  together.  The  sides  should  always 
be  glazed  with  transparent  glass. 

Curtains. — The  best  system  of  all  is  that  of  Loescher  &  Petsch.  The 
old  system  of  Loescher  &  Petsch,  as  explained  on  page  19,  is  cheaper 
than  the  new  one. 

White  and  lace  curtains  are  superfluous.  The  latter  do  not  pre- 
vent the  light  from  entering,  but  only  modify  it.  The  same  effect  is 
produced  with  dark  curtains  by  narrowing  the  opening  through  which 
the  light  enters.  We  would  remark,  in  conclusion,  that  the  curtains 
must  be  carefully  handled.  In  damp  weather  the  cords  should  be 
slackened  to  prevent  their  snapping,  and  even  the  most  perfect  arrange- 
ment will  still  leave  something  to  be  desired. 

The  American  ateliers  are  generally  very  high,  and,  in  this  respect, 
well  suited  for  taking  groups  and  drawings.  For  the  taking  of  single 
portraits,  however,  they  are  inferior  to  low  ateliers.  We  know  very 
well  that  there  are  high  skylights  in  America  in  which  splendid  single 
portraits  have  been  made,  but  it  does  not  follow  by  any  means  that 
the  high  skylight  is  advantageous  for  taking  single  portraits.  We 
refer  to  what  has  been  said  previously  on  the  subject. 

Of  the  Glass. — For  the  glazing  of  the  atelier  a  good  and  as  nearly 
colorless  glass  as  possible  should  be  selected.  It  must  be  free  from 
manganese.  Glass  containing  the  latter  substance  will  in  course  of 
time  turn  yellow  and  obstruct,  in  a  measure,  the  passage  of  the  actinic 
rays.  This  is  the  reason  why  in  many  ateliers  the  light  gets  worse 
from  year  to  year. 

Blue  glass  is  not  to  be  recommended.  Mr.  Gaflield  has  shown  that 
blue  glass  obstructs  the  passage  of  the  chemical  rays  to  a  much  larger 
extent  than  white  glass. 

Ground-glass  is  also  sometimes  employed  for  glazing  the  skylight. 
The  roof  of  Adam  Salomon's  atelier,  for  instance,  is  glazed  with  this 
substance.  It  absorbs  about  50  per  cent,  of  light,  while  white  glass 
will  absorb  only  about  5  per  cent. 

To  the  photographer  who  does  not  know  how  to  manage  his  curtains 
in  order  to  produce  the  best  effect,  we  would  recommend  to  cover  his 
skylight  with  ground-glass.  It  modifies  and  mellows  the  effect  of  too 
strong  a  front-light.  Ground-glass  also  is  advantageous  to  prevent 
reflexes  of  sunlight  in  certain  parts  of  the  atelier  which  are  exposed 
to  direct  sunlight.    Ordinary  glass,  however,  by  being  covered  with 


DISTRIBUTION  OF  LIGHT  IN  THE  STUDIO.  31 


a  thick  starch  paste,  will  act  similar  to  ground-glass.  A  wash  of  warm 
water  will  easily  remove  this  covering.  Hance's  Ground-glass  Substi- 
tute answers  all  the  purposes  of  ground-glass. 

To  keep  the  glass  clean  on  the  outside  is  of  great  importance.  When 
the  rain  does  not  perform  this  duty  the  glass  should  frequently  be 
washed.  A  hose  attached  to  the  water-pipe  is  very  serviceable  for 
this  purpose. 

Ventilation. — Frequent  change  of  air  is  necessary.  For  this  pur- 
pose the  atelier  of  the  Academy  is  provided  with  four  small  windows, 
below  the  side  light  near  the  floor.  Besides,  the  rear  wall  of  the  ate- 
lier is  provided  with  four  large  openings  at  its  highest  point  (ventila- 
tors). 

Heating  is  best  accomplished  by  iron  stoves,  and  a  good  coal  or 
wood  fire.  A  heating  material  which  gives  out  heat  rapidly  should 
be  selected,  as  the  glass  cools  off  very  rapidly. 

Paint. — The  walls  of  the  gallery  reflect  a  certain  amount  of  light ; 
this  light  falls  on  the  shaded  side  of  the  model  and  illuminates  it. 
When  the  wall  is  red  the  shadow  will  also  be  red,  which  can  readily 
be  seen  by  looking  at  the  picture  of  a  plaster  model  on  the  ground- 
glass  of  the  camera,  when  the  eye  is  protected  by  the  focussing-cloth. 
But  red  light  does  not  affect  the  sensitive  film,  neither  does  brown. 
The  walls  should  therefore  be  painted  light  blue, — cobalt  blue.  This 
gives  effective  light. 

For  a  description  of  reception-rooms,  see  the  remarks  on  Messrs. 
Loescher  &  Petsch's  atelier. 

Printing-room. — About  the  arrangement  of  the  printing-room  we 
have  spoken  before.  Loescher  &  Petsch  have  theirs  under  the  gal- 
lery. In  Fig.  10  we  represent  an  arrangement  that  is  much  in  vogue 
in  high  buildings.  In  this  instance  the  printing  place  is  above.  It 
forms  a  smaller  skylight,  simpler  in  construction,  and  10  feet  high. 
The  main  gallery  should  be  built  of  glass  and  iron ;  this  is  rather 
dear  but  solid.  The  printing-room  may  be  made  of  wood  and  glass. 
The  platform  in  front,  p.  29,  is  for  printing  in  the  open  air. 


PRINCIPLES  OF  DISTRIBUTION  OF  LIGHT  IN  THE  STUDIO. 

v  Experience  has  demonstrated  that  in  all  constructions  of  ateliers 
the  principle  of  excluding  direct  sunlight,  and  of  working  with  the 
diffused  light  of  heaven,  is  found  to  be  the  best. 

The  reasons  for  this  we  shall  explain  in  the  second  part  of  this 
book. 

To  exclude  direct  sunlight  the  glass  surfaces  face  the  north  as  much 


32 


THE  PRACTICE  OF  PHOTOGRAPHY. 


as  possible,  and  to  obtain  the  largest  amount  of  diffused  light  the 
glass-houses  are  erected  on  the  tops  of  high  buildings,  or  in  places 
where  the  horizon  on  the  glass  side  is  free  from  objects  which  would 
obstruct  the  light.  In  cities  this  is  not  always  possible,  and  frequently 
a  considerable  portion  of  the  vault  of  heaven  is  cut  off  from  view. 
The  light  which  is  reflected  from  buildings  is  not  always  useless,  but 
its  intensity  is  a  different  one.  Sometimes  it  is  lighter  (when  reflected 
from  a  white  wall)  or  darker,  and  this  circumstance  becomes  an 
annoyance  when  the  light  is  to  be  distributed  properly  by  an  arrange- 
ment of  curtains. 

Not  only  the  quality  and  quantity  of  light  is  essential  in  the  use  of 
a  glass-house,  but  also  the  direction  in  which  it  strikes  the  sitter  has 
to  be  taken  into  consideration. 

In  the  second  part  we  shall  give  three  photographic  portraits  as 
illustrations,  taken  with  front-light,  top-light,  and  side-light,  and  it 
will  be  noticed  that  front-light  is  the  most  unfavorable,  while  side- 
light is  the  most  favorable.  Leaving  the  explanation  of  this  point  for 
the  aesthetic  portion  of  our  work,  we  will  only  mention  that  nobody 
should  take  a  portrait  exclusively  with  side-light,  but  that  in  the  best 
portraits  from  the  most  celebrated  ateliers  this  light  predominates. 
From  this  standpoint  we  cannot  advocate  a  construction  like  Monck- 
hoven's,  in  which  the  front-light  predominates ;  it  would  appear  more 
useful  when,  as  shall  be  explained  further  on,  the  side-light  could  be 
widened  and  the  front-light  made  narrower. 

For  the  better  understanding  of  the  distribution  of  light  in  an 
atelier,  we  must  explain  the  main  principles  of  illumination  in  a  glazed 
space. 

We  take  for  instance  a  room  which  receives  its  light  through  a 
window  from  the  clear  blue  sky.  Experience  teaches  us  that  the 
light  in  such  a  room  is  very  unequal  in  different  places ;  the  further 
an  object  is  removed  from  the  window  the  darker  it  will  appear,  and 
vice  versa;  but,  besides  the  distance  from  the  window,  the  position 
towards  it  becomes  of  importance.  A  point  close  to  the  window  will 
appear  darker  than  one  equally  far  removed  but  opposite  to  it. 

Let  us  explain  the  cause  of  this  appearance.  Excluding  direct  sun- 
light, the  sky  is  the  only  source  of  light  which  illuminates  the  objects 
in  the  room,  and  an  object  will  be  lighter  in  proportion  to  the  number 
of  rays  it  receives  from  the  sky. 

Taking  for  instance  the  point  a  (Fig.  11),  which  is  opposite  a  cir- 
cular window,  the  latter  receiving  a  cone  of  rays  of  the  size  of  the 
diameter  of  the  window.    We  take  a  second  point,  a' ;  this  point  is 


DISTRIBUTION  OF  LIGHT  IN  THE  STUDIO. 


33 


illuminated  by  the  cone  6,  a,  c,  which  is  considerably  smaller.  Still 
more  pointed  appears  the  cone  which  illuminates  the  point  e,  and  thus, 
it  is  explained  why  a  will  appear  brighter  than  a',  and  a'  brighter 


Fig.  11. 


a  > 


than  e.  The  opening  of  the  cones  of  rays,  or  the  angle  which  is 
formed  by  drawing  lines  from  the  point  in  question  towards  the 
window,  gives  us  a  criterion  of  its  relative  brightness.  I  call  this 
angle  the  angle  of  light. 

When  we  take  a  point  on  the  wall  containing  the  window,  the  angle 
will  be  reduced  to  a  line,  and  would  be  absolutely  dark  if  it  did  not 
receive  light  by  reflection. 

It  is  evident  that  not  only  the  wall  in  which  the  window  is,  but 
also  every  other  point  in  the  room,  receives  this  reflected  light  from 
walls,  floor,  and  ceiling.  Every  point  in  the  room,  the  wall  with  the 
window  excepted,  is  struck  by  two  different  masses  of  light. 

1st.  The  direct  light  of  the  sky,  the  quantity  of  which  is  propor- 
tionate to  the  extent  of  the  effective  spherical  surface  of  the  vault  of 
heaven. 

2d.  The  reflected  light  of  the  walls,  &c,  &c,  the  nature  of  which 
is  more  complicated. 

Let  us  look  aside  for  the  present  from  the  reflected  light  and  con- 

3 


34 


THE  PRACTICE  OF  PHOTOGRAPHY. 


sider  the  action  of  direct  sunlight.  The  illumination  produced  from 
this  source  we  will  call,  for  the  sake  of  brevity,  the  direct  brightness. 

The  direct  brightness  of  a  point  in  the  room  is,  as  has  been  explained 
above,  dependent  on  its  position  to  the  window,  and  on  the  size  of  the 
latter. 

For  the  better  explanation  of  this  point  we  will  start  from  the 
plainest  proposition,  and  consider  the  brightness  of  a  point  directly 
opposite  to  a  small  round  window.  The  larger  the  window,  the  larger 
will  be  the  angle  of  light.  Suppose  the  angle  of  light  should  be  small, 
then  the  brightness  of  a  point  will  be  proportionate  to  the  surface  of 
the  window.  In  similar  figures,  the  surfaces  are  proportioned  as  the 
squares  of- similar  lines,  and  accordingly  the  brightness  would  be  pro- 
portioned as  the  squares  of  the  diameters  of  the  windows. 

A  window  twice  as  large,  be  it  round  or  square,  will  give  for  the 
same  point  four  times  as  much  light,  and  one  of  three  times  the  size 
nine  times  as  much.  With  larger  window  openings  the  increase  of 
brightness  by  increasing  the  opening  is  not  so  marked.  We  take  for 
instance  a  point,  a  (Fig.  12),  which  is  opposite  the  opening,  c  b,  in 


Fig. 12. 


the  otherwise  darkened  glass-house.  Half  the  angle  of  light  would 
be,  in  this  case,  a,  and  when  we  increase  the  opening  successively  to 
twice  the  size,  o  b',  or  three  times,  o  b" ,  and  four  times,  o  b'n,  the  angle 
of  light  at  a  will  be  increased  by  the  piece  a',  a",  a"\  which,  as  will 
be  seen  by  the  figure,  increases  less  rapidly  than  the  size  of  the  window- 
opening.    We  can  draw  from  this  at  once  a  practical  conclusion. 


DISTRIBUTION  OF  LIGHT  IN  THE  STUDIO.  35 


Fig.  13. 


If  in  a  glass-house  of  32  feet  in  length,  a  person,  a  (Fig.  13),  is  placed 
5  feet  from  the  glass  side  and  4 
feet  from  the  background,  and 
the  glass  side  is  open  from  g  to 

h,  we  will  have  a  criterion  of  the 
amount  of  light  which  the  person 
receives  by  constructing  the  an- 
gle h,  a,  g.  The  portion  of  the 
vault  of  heaven  which  is  cut  by 
the  angle  h,  a,  g,  determines  the 
brightness  of  the  point  a. 

If  the  length  of  the  atelier 
should  be  24  feet  instead  of  32 
feet,  that  is,  if  it  terminated  at 

i,  then  the  brightness  would  be 
determined  by  the  angle  i,  a,  g, 
all  other  circumstances  being 
equal.  A  glance  at  the  figure 
will  show  that  the  angles  i,  a,  g, 
and  h,  a,  g,  are  not  very  differ- 
ent— i.  e.,  that  in  this  especial 
case  the  extension  of  the  glass 
wall  by  8  feet  beyond  i  (by  the 
piece  i  h)  would  not  secure  any 
great  advantages,  particularly  as 
the  light  which  strikes  the  glass  side  h  i,  under  a  very  oblique  angle, 
is  for  the  most  part  reflected. 

As  we  increase  the  distance  from  the  window  we  decrease  the  angle 
of  light. 

A  simple  mathematical  consideration  leads  to  the  result  that  the 
brightness  of  two  points,  which  are  located  opposite  a  window,  decreases 
at  the  same  ratio  as  the  distances  from  the  window  increase. 

When  we  remove  an  object  twice  as  far  from  the  glass  side  of  the 
atelier,  we  must,  in  order  to  secure  the  same  brightness,  open  the  cur- 
tains twice  as  wide,  in  order  that  the  light-giving  glass  surface  be  four 
times  as  large  as  when  the  object  is  near  the  glass  side,  or  we  must 
extend  the  time  of  exposure  fourfold  in  order  to  secure  the  same  re- 
sult. When  the  window  is  very  large  the  brightness  will  not  decrease 
quite  as  rapidly  with  an  increase  of  the  distance — i.  e.,  at  twice  the 
distance  the  brightness  will  be  a  little  more  than  one-fourth,  at  three 
times  a  little  more  than  one-ninth. 

From  the  above  considerations  we  may  draw  a  practical  conclusion 


36 


THE   PRACTICE  OF  PHOTOGRAPHY. 


and  answer  a  question  which  of  late  has  been  asked  quite  frequently, 
namely  :  "  Which  is  the  most  practical,  a  high  or  a  low  atelier?"  But 
we  have  to  answer  another  question  first :  For  what  purposes  is  the 
atelier  intended  ? 

An  atelier  may  be  perfectly  adapted  to  the  taking  of  single  por- 
traits, while  it  may  be  unsuited  to  the  taking  of  groups  or  reproduc- 
tions, and  vice  versa.  Ateliers  like  Keutlinger's  or  Adam  Salomon's, 
are  excellent  for  taking  single  portraits,  while  they  are  unsuited  to 
taking  groups. 

The  reason  of  this  is  easily  explained.  In  copying  large  paintings 
or  drawings  we  require  a  uniform  illumination  over  the  whole  of  the 
original,  while  with  a  single  portrait  the  reverse  is  the  case.  The 
head,  which  is  the  principal  object,  should  be  lighter,  while  the  other 
less  characteristic  parts  should  be  kept  in  half  shadow.  These  are 
artistic  qualities  which  in  a  high  degree  are  visible  in  the  portraits 
of  Adam  Salomon,  and  less  strikingly  in  those  of  Carl  V.  Jageman  in 
Vienna. 

If  we  should  try  to  take  a  group  under  the  same  conditions  of  illu- 
mination, only  one  person  would  appear  properly  lighted,  while  all 
the  rest  would  be  in  half  shadow  and  scarcely  visible. 

To  answer,  therefore,  the  above  question  we  must  consider  first  the 


be  as  400  to  625  =  16  to  25,  or  nearly  as  2  to  3. 

Suppose,  further,  we  have  an  atelier  10  feet  high,  all  other  condi- 


Fig.  14. 


purpose  for  which  the  ate- 
lier is  constructed  ;  and  I 
will  take  the  simplest  case 
first, — the  construction  of 
an  atelier  for  single  por- 
traits. 


Suppose  we  have  an  ate- 
lier (Fig.  14)  about  25 
feet  high,  and  in  it  an  ob- 
ject, for  instance,  a  person, 
a'  k'y  5  feet  high.  Above 
the  person  is* an  opening, 
b  c,  in  the  glass  roof  of  a 
given  size.  The  distance 
of  the  head  from  the  roof 
would  be  equal  to  20  feet, 
and  the  distance  of  the 
floor  —  25  feet ;  hence  the 
brightness  of  the  two  would 


DISTRIBUTION  OF  LIGHT   IN  THE  STUDIO.  37 

tions  being  equal.  In  this  case  the  head,  k,  would  be  5  feet  distant 
from  the  floor,  and  the  feet,  a,  =  10  feet ;  the  brightness  of  the  two 
would  be  as  1  to  4. 

It  sho\^  how  important  these  differences  are.  In  the  first  case,  in 
a  bright  atelier,  the  head  receives  only  one  and  a  half  times  as  much 
light  as  the  feet :  in  the  second  case  four  times  as  much.  What  is 
the  consequence?  In  the  former  case  we  have  slight  contrasts  of 
light  and  shade,  while  in  the  latter  they  are  very  strong. 

In  a  portrait  the  head  is  the  principal  object*  the  head  should 
receive  the  main  light.  A  contrast  of  light  and  shade  between 
hands  and  feet  in  the  proportion  of  2  to  3  is  not  sufficient  to  mark 
brilliant  contrasts  in  the  picture.  A  difference  of  1  to  4  gives  much 
more  effect.  From  this  standpoint  a  low  atelier  has  the  advantage 
for  taking  single  portraits.  As  an  example  of  such  low  ateliers  I 
would  mention  those  of  Adam  Salomon  and  Eeutlinger  in  Paris. 

The  case  is  quite  different  when  we  take  groups  or  drawings,  where 
an  illumination  which  is  equally  divided  over  the  whole  surface  is 
desired.  Sigh  ateliers  are  in  this  case  desirable.  But  we  can,  in  a 
low  atelier,  produce  the  same  effect  when  the  glass  roof  is  sufficiently 
wide,  or  of  a  width  equal  to  the  group. 

When,  on  the  other  hand,  we  wish  to  obtain  in  a  high  atelier  the 
same  effects  as  in  a  low  one,  we  will  do  well  to  place  the  persons 
under  screens  or  curtains,  which  are  placed  at  a  height  of  about  10 
feet  above  them. 

While  explaining  these  principles  we,  for  the  present,  do  not  take 
into  account  the  light  which  is  reflected  from  the  walls,  nor  the  amount 
of  light  lost  by  reflection  in  passing  through  the  windows.  Any  one 
who  has  read  the  preceding  directions  attentively  will  find  no  difficulty 
in  solving  different  problems  in  regard  to  the  brightness  of  a  given 
point  in  the  atelier.  For  small  openings  of  light  it  is  easy  to  calcu- 
late the  brightness  of  a  point  in  the  room  according  to  the  formulae 
given  hereafter,  but  with  larger  glass  surfaces  the  construction  of  the 
angle  of  light  will  give  the  best  criterion. 

For  this  purpose  a  drawing  of  the  atelier  (or  a  part  of  the  same 
containing  the  point  in  question,  and  the  area  of  glass  surface  trans- 
mitting the  light)  is  made  in  ground-plan  and  vertical  section,  and 
the  angle  of  light  is  constructed  both  in  the  vertical  and  horizontal 
plane. 

From  the  above  principles  a  criticism  on  the  construction  of  the 
atelier  follows  as  a  matter  of  course. 

Let  us  take  as  an  example  the  atelier  (Fig.  13)  which  has  a  north- 
ern front.    It  is  32  feet  long  and  16  feet  wide;  it  shows  closed  walls 


38 


THE  PRACTICE  OF  PHOTOGRAPHY. 


and  a  glass  front,  h  g.  The  scale  is  given.  Suppose  a  person  be  at 
a,  5  feet  from  the  window  and  4  feet  from  the  rear  wall,  the  glass  side 
to  be  open  from  g  to  h,  or  28  feet.  We  will  get  the  effect  of  the  28 
feet  glass  side  by  constructing  the  angle  h,  a,  g.  Suppose^we  take 
instead  of  the  long  glass  side,  g  h,  an  inclined  one,  g  k,  of  only  8  feet 
in  length.  The  angle,  k,  a,  g,  will  be  exactly  as  large  as  the  angle 
h,  a,  g,  or  the  small  glass  side  of  only  8  feet  will  admit  as  much  light  as 
the  large  one,  g  h,  of  28  feet  in  length. 

Even  a  glass  side,  g  I,  of  only  5  feet  in  length,  would  give  as  much 
light  on  a  person  at  a,  and  be  unprofitable  only  in  so  far  as  seen  from 
A  (where  the  apparatus  has  been  placed) ;  a  part  of  the  field  of  view 
would  be  cut  off  by  the  edge  I. 

We  have  shown  that  for  taking  the  picture  of  a  person  at  a  the 
large  glass  side  of  28  feet  in  length  can  be  replaced  by  a  much  smaller 
one  placed  at  an  inclination,  the  size  of  which  need  only  to  be  8  feet, 
without  detriment  to  the  brightness  of  the  illumination.  What  holds 
good  for  the  side  applies  with  equal  force  to  the  roof.  The  surface  of  28 
feet  in  length  can  be  replaced  by  an  inclined  one  of  only  8  feet. 

When  we  construct  an  atelier  with  such  a  glass  side  and  an  analo- 
gous roof,  we  will  have  a  space  which  apparently  equals  in  brightness 
the  large  atelier  of  32  feet  in  length. 

Such  an  atelier  would  resemble  the  following  figure  (Fig.  15). 

The  parts  not  shaded  are  glazed ;  the  others  are  dark ;  the  appara- 
tus would  stand  in  the  dark  parts,  T,  T;  the  person  would  be  at  a, 
near  the  glass  side.  The  depth  of  the  glass  roof  we  have  taken  at  12 
feet.  For  single  portraits  this  would  not  only  be  sufficient,  but  for 
most  cases  in  excess,  and  only  in  exceptional  cases  the  whole  roof 
could  be  employed. 

Starting  from  simple  principles  of  illumination  we  have  reached  an 
atelier  construction  which  has  often  been  adopted,  although  in  differ- 
ent proportions.  It  is  the  so-called  tunnel  atelier,  and  we  have  shown 
that  for  taking  single  portraits,  observing  the  explained  conditions,  it 
answers  every  purpose  in  regard  to  the  quantity  of  light  as  well  as  a 
large  north  front  atelier.  For  amateurs  and  small  photographers, 
but  only  for  these,  such  a  building  would  answer  every  purpose. 

The  best  position  for  the  side  is  due  north.  In  this  way  the  side 
light  is,  as  the  main  light,  most  effectually  excluded  from  the  direct 
rays  of  the  sun.  The  roof  must  be  protected  by  awnings  from  the 
direct  sunlight.  Where  the  saving  of  room  is  an  object,  the  depth 
can  be  reduced  to  16  feet.  Such  an  atelier  would  answer  for  single 
portraits,  and  would  recommend  itself  on  account  of  its  cheapness ; 
still  it  has  disadvantages  when  compared  with  a  north  front  atelier. 


DISTRIBUTION  OF  LIGHT  IN  THE  STUDIO.  39 


In  the  first  place,  the  person  always  receives  the  light  from  the  same 
side.  In  the  above  instance  from  the  right,  while  an  atelier  fronting 
north  admits  of  illumination  from  right  or  left  by  placing  the  person 
so  as  to  face  east  or  west. 

This  disadvantage  is  not  of  great  moment.  In  all  of  Reutlinger's 
pictures  the  light  comes  from  the  right-hand  side. 


Fig.  15. 


A  greater  disadvantage  shows  itself  when  the  person  is  not,  as  we 
have  proposed,  seated  near  the  glass  side,  but  is  removed  from  it. 

Suppose  a  person  is  placed  at  b  (Fig.  13),  twice  as  far  from  the 
glass  as  a,  we  will  see  by  drawing  the  lines  b  h,  and  b  k,  the  light- 
effect  which  the  two  sides  g  h  and  g  k  will  produce ;  and  here  it  be- 
comes evident  that  the  angle  h,  b,  g,  is  much  larger  than  k,  b,  g,  or 
that  for  a  point  removed  from  the  glass  side  the  illumination  is  in  a  north 
front  atelier  much  more  favorable. 

In  a  tunnel  atelier  we  are  confined  to  the  space  in  the  immediate 
neighborhood  of  the  light,  while  a  north  front  atelier  permits  of  greater 
depth,  and  the  latter  gives  not  only  a  greater  space  for  artistic  arrange- 
ment, but  also  a  decidedly  better  light  for  taking  groups. 

The  advantages  of  a  north  front  atelier  are  easily  understood  there- 
fore. 


40 


THE  PRACTICE  OF  PHOTOGRAPHY. 


CHAPTER  II. 

SECTION  I. 
THE  FURNISHING  OF  THE  GALLERY. 

In  the  previous  chapter  having  become  acquainted  with  the  im- 
movable objects  of  the  gallery,  we  will  now  proceed  to  the  considera- 
tion of  the  movable  ones. 

These  will  vary  with  the  purpose  to  which  the  gallery  is  devoted. 
In  a  portrait  gallery  they  will  differ  from  the  furniture  of  an  estab- 
lishment devoted  mainly  to  copying,  and  portrait  galleries  are  again 
furnished  with  more  or  less  luxury,  according  to  the  standing  of  the 
public  with  which  the  artist  has  to  deal,  or  to  his  own  personal  taste. 

We  will  confine  our  remarks  to  those  objects  which  belong  to  an 
atelier  for  the  production  of  portraits,  reproductions,  and  the  taking 
of  pictures  of  plastic  objects. 

The  work  to  be  performed  in  the  gallery  is  of  a  twofold  character. 

1.  Arrangement  of  the  model. 

2.  Arrangement  of  the  apparatus. 

The  arrangement  of  the  object  which  is  to  be  taken  is  sometimes 
very  easy,  as  the  placing  on  a  board  of  a  print  to  be  copied.  Some- 
times, however,  the  arrangement  may  offer  great  difficulties ;  for  in- 
stance, with  a  living  object  which  has  a  will  of  its  own  and  generally 
will  offer  some  resistance,  not  to  speak  of  the  fact  that  it  has  to  be 
placed  in  the  most  pleasing  position  according  to  its  individuality ; 
that  it  has  to  be  properly  lighted  and  must  be  brought  in  harmony 
with  the  surrounding  objects,  even  if  these  should  consist  only  of  a 
few  pieces  of  furniture.  We  must  also  take  into  account,  that  the 
optical  apparatus  must  be  in  condition  to  take  in  the  whole  arrange- 
ment with  the  greatest  possible  sharpness  and  within  as  short  a  time 
of  exposure  as  possible.  The  picturesque  and  the  optical  standpoint 
have  both  to  be  considered  (very  often  the  one  or  the  other  is  over- 
looked). 

The  artistic  standpoint  will  be  fully  considered  in  the  sesthetical 


■ 


THE  FURNISHING  OF  THE  GALLERY.  41 

portion  of  this  work ;  at  present  we  will  only  take  the  mechanical 
arrangements  into  consideration. 

When  I  focus  a  lens  sharply  on  any  object,  say,  for  instance,  a  per- 
son, I  will  find  that  other  objects,  back  or  at  the  side  of  the  sitter, 
appear  also  in  the  picture,  materially  influencing  the  beauty  of  the 
same. 

4 

These  are  either  entirely  left  out  by  placing  the  object  in  front  of  a 
monotonous  gray  or  more  or  less  dark  wall,  which  is  called  the  back- 
ground, or  the  accessories  are  so  arranged  that  with  the  main  object 
they  form  a  harmonious  picture. 

The  backgrounds  are  either  made  of  cloth  (the  so-called  "background 
cloth,"  which  is  expressly  woven  for  this  purpose),  or  they  are  painted 
on  canvas  or  shirting  with  oil-paint,  which  is  laid  on  as  homogeneous 
and  dull  as  possible.  The  background  stuff  is  best  placed  on  a  frame 
analogous  in  its  construction  to  the  frames  of  the  painters,  which  can 
be  tightened  by  means  of  wedges,  as  circumstances  may  require. 

The  background  may  be  hung  on  rails,  E,  E,  and  the  upper  part 
provided  with  rollers,  B,  E,  as  is  represented  in  Fig.  16. 

Such  backgrounds  are  easily  pushed  aside,  provided  the  atelier  is 
wide  enough.  The  atelier  must  have  as  many  rails  as  backgrounds, 
as  every  background  has  to  run  on  its  own  rail. 

Small  ateliers  require  different  arrangements.  The  background  is 
placed  on  rollers  and  moved  from  place  to  place  as  required,  or  the 
background  is  not  mounted  at  all,  but  rolled  up  like  a  curtain.  All 
the  backgrounds  in  Reutlinger's  atelier  are  arranged  as  curtains.  Six 
to  eight  such  curtains,  one  behind  the  other,  and  parallel  to  each 
other,  are  placed  at  the  spot  where  the  sitter  is  placed.  But  the 
backgrounds  suffer  by  being  rolled  and  unrolled  so  frequently,  par- 
ticularly when  they  are  painted  with  scenic  or  landscape  effects.  The 
wider  the  background  the  better  it  will  be  for  the  arrangement. 

In  regard  to  the  employment  of  painted  backgrounds  full  directions 
will  be  found  in  the  sesthetical  portion  of  this  work. 

For  the  suitable  arrangement  of  the  model  other  objects  are  neces- 
sary, according  to  the  nature  of  the  same,  such  as  pillars,  balustrades, 
furniture,  curtains,  &c.  But  most  photographers  do  too  much  of  a 
good  thing.  They  have  a  complete  furniture  store  in  their  ateliers. 
Eminent  artists  will  get  along  with  the  simplest  accessories.  All 
such  objects  should  be  so  arranged  that  they  can  be  placed  in  position 
in  the  shortest  time,  and  be  removed  again  at  a  moment's  notice  with- 
out any  noise  or  confusion. 

Generally  the  sitters  are  in  a  hurry  and  wish  to  be  taken  in  a  short 


42 


THE  PRACTICE  OF  PHOTOGRAPHY. 


time,  even  if  the  time  of  the  photographer  should  not  be  especially 
occupied. 

With  this  simple  arrangement,  however,  the  original  is  not  suffi- 
ciently prepared.  An  important  point  is  that  during  the  exposure 
perfect  steadiness  should  be  secured.  With  lifeless  objects  this  is 
easily  accomplished;  they  are  placed  on  a  solid  foundation  and 
fastened  to  it. 

With  a  living  model  the  case  is  entirely  different.    No  one  can  sit 


Fig.  16. 


absolutely  still.  Every  pulsation  causes  an  imperceptible  motion, 
and  just  at  the  moment  of  exposure,  when  the  model  is  conscious  that 
on  his  steadiness  success  depends,  the  spirit  is  most  willing,  but  the 
flesh  is  weakest,  particularly  the  most  important  part  of  all  the  flesh — 
the  head.  Nothing  can  prevent  this  evil  but  the  use  of  the  head- 
rest, against  which  the  public  obstinately  protests,  but  upon  the  em- 
ployment of  which  the  photographer  must  just  as  obstinately  insist. 
It  should  not  be  brought  into  use  until  all  the  other  arrangements 
are  finished,  and  everything  is  ready  for  the  taking  of  the  picture. 


THE  FURNISHING  OF  THE  GALLERY. 


43 


Then  the  "rest"  should  be  adapted  to  the  sitter,  and  not  vice  versa. 
The  person  who  tries  to  force  the  sitter  to  the  head-rest  is  guilty  of 
"  cruelty  to  animals,"  and  is  a  sinner  against  good  taste  in  the  bar- 
gain. It  is  self-evident  that  this  necessary  evil  must  not  be  visible  in 
the  picture,  a  circumstance  which  often  very  sadly  ties  the  hands  of 
the  photographer  in  making  his  arrangements. 

Fig.  17  shows_  the  construction  of  the  head-rest  generally  used  in 
the  United  States,  and  which  is  called  "  Wilson's  Improved  Rest." 

For  standing  figures  the  rest 
requires  great  firmness,  and 
the  American  pattern  seems 
to  be  preferable,  and  all  that 
is  required.  The  joints  should 
be  frequently  examined,  and 
care  should   be  taken  that 
everything  moves  easy  and 
without     noise.  Frequent 
cleaning  and  oiling  is  advisa- 
ble.   The  American  rests  of 
less  complicated  and  cheaper 
form  are  familiar  to  all,  known 
as  Scovill's,  the  Tuscan,  &c. 
For  the  copying  of  paintings 
and  engravings,  an  easel  is  generally  used.  The 
form  is  very  well  known.    But  for  photographic 
purposes  the  easel  would  not  be  very  practical. 
Generally  they  stand  inclined,  and  the  picture,  of 
course,  has  the  same  inclination,  and  when  we 
wish  to  avoid  distortion,  the  camera  has  to  be  in- 
clined to  the  same  extent.    For  work  re- 
quiring great  exactness  this  is  not  sufficient, 
and  it  is  preferable  to  employ  a  vertical 
stand  on  which  a  movable  drawing-board 
can  be  fastened. 

Fig.  18  represents  such  an  arrangement. 
It  consists  mainly  of  the  board,  B,  with  the  ledge,  r,  r,  which  serves 
as  a  rest  for  oil-paintings  or  drawing-boards.  It  can  be  moved  in  a 
vertical  direction,  and  by  the  binding-screw,  K,  kept  in  position  so 
that  plates  of  different  size  can  be  firmly  held.  By  a  cord  passing 
over  rollers  and  worked  by  the  handle,  F,  the  whole  is  easily  raised 
or  lowered. 


44 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Drawings  should  be  fastened  to  a  drawing-board,  which  is  placed 
on  the  ledge,  r,  r,  and  kept  in  place  by  the  screw,  K. 

The  whole  apparatus  is  easily  moved  from  place  to  place  in  the 
atelier  wherever  the  illumination  is  the  most  favorable. 


Fig.  18. 


(A 

/\  

r 

For  copying  plans,  where  absolute  mathematical  precision  is  re- 
quired, the  camera  should  be  firmly  connected  with  the  stand  which 
carries  the  original  in  such  a  manner  that  they  cannot  change  their 
relative  position  to  one  another. 

When  the  object  has  been  duly  prepared  the  arrangement  of  the 
optical  apparatus  is  next  in  order. 

Accordingly  as  we  wish  to  get  larger  or  smaller  pictures  of  an  ob- 
ject, the  optical  apparatus  has  to  be  removed  or  brought  closer  to  the 
original,  and  therefore  it  should  be  easily  removable.  Hence  the  ap- 
paratus is  generally  placed  on  a  stand.  But  as  the  different  objects 
vary  greatly  in  their  height  and  breadth,  the  stand  is  supplied  with  a 
vertical  and  horizontal  motion. 

The  construction  of  the  stand  is  more  or  less  massive  according  to 
the  size  and  weight  of  the  apparatus. 

Fig.  19  and  Fig.  20  show  two  of  the  forms  most  generally  in  use. 
Fig.  19  is  better  adapted  for  lighter  cameras,  while  Fig.  20  (the 


THE  CAMERA. 


45 


Fig.  19. 


Fig.  20. 


American  Optical  Company's  "Perfect"  camera-stand)  answers  for 
heavier  ones.  With  the  latter  the  vertical  movement  is  accomplished 
by  a  handle  and  rack  move- 
ment. The  binding  screw  is  to 
keep  the  apparatus  in  any 
given  position.  The  inclined 
position  of  the  board  is  gener- 
ally only  employed  in  portrait- 
ure. It  enables  the  operator 
to  secure  more  nearly  equal 
sharpness  to  the  whole  figure. 
The  stands  with  rollers  require 
a  point  which  is  driven  in  the 
floor  to  give  them  steadiness. 
In  bringing  the  stand  in  posi- 
tion the  beginner  should  take 
notice  that  in  moving  the  bar 
in  a  vertical  direction  the  pic- 
ture on  the  ground-glass  will 
move  in  the  same  direction. 

Iron  stands  have  also  been 
introduced ;  but  generally  these 
are  too  heavy  and  ruin  the  floor 
or  the  carpets.  Arrangements 
have  also  been  made  by  which 
the  rollers  can  be  fixed  in  posi- 
tion and  give  perfect  stability 
to  the  apparatus. 


SECTION  II. 

THE  CAMERA. 

The  camera,  in  order  to  se- 
cure exact  focussing,  should 
be  connected  with  the  stand  as 
closely  as  possible,  so  that  the 
position  will  not  change.  A 
camera  which  is  merely  placed 
on  the  stand,  is  easily  moved 
and  often  gives  rise  to  faulty 
pictures.  This  is  particularly 
the  case  with  light  instruments, 
own  weight. 


Heavy  ones  will  stand  firm  by  their 


46 


THE  PRACTICE  OF  PHOTOGRAPHY. 


The  photographic  camera  is  one  of  the  simplest  optical  instruments. 
It  consists  of  a  box  which  is  often  formed  of  a  pair  of  bellows  only. 
The  end,  which  is  turned  towards  the  object,  is  furnished  with  a  lens 
called  the  objective,  and  the  other  end  is  provided  with  a  plate  of 
ground-glass,  which  latter  can  be  moved  nearer  to  or  further  from  the 
objective.  The  box  or  the  bellows  serve  to  produce  a  dark  space.  It 
is  necessary  that  this  should  be  absolutely  dark,  a  circumstance  of 
which  one  must  satisfy  oneself  in  buying  a  new  instrument  by  placing 
the  head  inside  the  camera,  excluding  all  outside  light  by  a  cloth, 
and  looking  carefully  for  cracks  which  might  admit  the  light. 

To  obtain  a  sharp  picture  the  plate  of  ground-glass  is  brought  more 
or  less  near  to  the  objective.  For  this  purpose  the  back  part  of  the 
camera,  h,  can  be  provided  with  guides,  s,  s,  which  run  in  grooves 
parallel  to  each  other.  The  screw,  r,  serves  to  fix  the  ground-glass  at 
the  desired  distance  from  the  objective. 


Fig.  21. 


When  the  part,  h,  is  brought  very  near  to  the  objective,  the  pro- 
jecting board,  s,  will  prevent  the  operator  from  bringing  his  face  very 
closely  to  the  ground-glassysand  make  perfect  focussing  rather  difficult.  * 
It  is  more  convenient  to  pull  out  the  front  part,  r,  which  moves  in 
grooves  inside  of  s  s.  When  the  picture  has  been  focussed  tolerably 
sharp  on  the  ground-glass,  the  finishing  touches  are  given  by  either 
the  rack  movement  on  the  lens  itself,  or  by  a  rack  movement  at  the 
rear  end  of  the  camera. 

The  screws  a  and  b  (Fig.  22)  should  be  loosened ;  the  back  part,  m, 
which  carries  the  ground-glass,  is  now  moved ;  a  is  screwed  tight,  and 


THE  CAMERA. 


47 


with  the  rack  movement,  Z  and  t,  the  fine  adjustment  is  made. 
Finally,  the  whole  arrangement  is  fixed  by  tightening  the  screw  b. 
In  this  way  our  German  camera  boxes  are  made. 

The  English  cameras,  to  facilitate  focussing,  are  provided  with  an 
endless  screw,  which  moves  the  object-board  0  (Fig.  21).  The  screw 
is  worked  by  a  crank.  This  arrangement  is  very  handy,  but  admits 
only  of  limited  motion. 


Fig.  22. 


A  better  arrangement  than  any  of  these  is  applied  to  the  boxes 
made  in  New  York  by  the  American  Optical  Company.  The  front 
part  of  the  frame  of  the  camera  box  is  made  fast  to  the  platform,  and 
the  focussing  is  done  with  the  back  part  of  »the  frame,  which  runs  on 
metal  guides  attached  to  the  sides  of  the  platform.  An  approximate 
focus  is  thus  obtained,  and  the  exact  focus  is  secured  by  means  of  a 
short  focussing  screw  which  works  in  a  groove  in  the  centre  of  the 
platform.  A  clamping  screw  fastens  the  whole  rigidly  in  place  when 
the  focus  is  obtained.    This  arrangement  may  be  seen  in  Fig.  29. 

When  the  focussing  has  been  accomplished,  the  ground-glass,  S  S 
(Fig.  21),  is  turned  back  and  in  its  place  the  plate-holder  is  pushed, 
carrying  the  sensitized  plate.  The  sensitive  plate  must  occupy  ex- 
actly the  same  position  which  the  ground-glass  has  occupied  before, 
or  the  picture  will  lack  sharpness. 

To  find  out  if  a  camera  works  correctly  in  this  respect,  the  lens  is 
removed  and  through  the  hole  a  rule  is  introduced.  The  distance 
between  the  ground-glass  and  the  front  of  the  camera  is  noted  down ; 
next  a  plate-holder  with  a  plate  of  glass  is  put  in  position  ;  the  shutter 
is  opened  and  the  distance  between  the  glass  and  the  front  of  the 
camera  is  noted  down.    When  the  two  exactly  correspond  the  plate- 


48 


THE  PRACTICE  OF  PHOTOGRAPHY. 


holder  is  correct.  Sometimes  the  ground-glass  admits  of  slight  move- 
ments by  means  of  the  so-called  double  swing-back.  This  motion  is 
of  advantage  for  the  sharp  focussing  of  such  objects  which  have  an 
inclined  position  to  the  axis  of  the  instrument. 


Fig.  23. 


The  swing-back  is  a  great  help  in  focussing  accurately  and  in  get- 
ting the  correct  figure  on  the  plate  without  trouble,  and  is  applied  to 
the  American  Optical  Company's  boxes.  Very  often  the  figure  is 
too  high  or  too  low  upon  the  plate.  A  vertical  motion  of  the  back 
of  the  camera,  one  way  or  the  other,  will  obviate  this  at  once.  So 
when  more  or  less  of  one  side  or  the  other  is  needed  in  the  picture  a 
lateral  motion  or  swing  at  once  secures  it.  The  back  is  then  secured 
in  place  by  the  clamps  and  screws  as  shown  in  Figs.  23  and  29. 

The  construction  of  the  plate-holder  is  easily  understood  from  the 
cut  (Fig.  24).  The  sensitive  plate  is  placed  in  the  frame,  B,  and 
rests  on  the  silver  wires,  d  d.  The  lid,  D,  is  now  closed  and  the 
spring,  /,  presses  firmly  on  the  plate  and  keeps  it  in  position.  The 
shutter,  JET,  remains  closed  and  is  only  opened  when  the  plate-holder 
has  been  placed  in  the  camera  and  everything  is  ready  for  the  ex- 
posure. 

The  wood  of  the  holder  is  apt  to  become  warped,  being  frequently 
moistened  by  the  drippings  of  silver  solution  from  the  plate.  The 
wood  should  be  well  oiled  and  varnished,  and  the  different  pieces 
should  be  joined  crossways,  one  upon  the  other,  and  all  the  different 
parts  well  dovetailed  together. 

In  Europe  the  shutters  of  large  plate-holders  are  frequently  pro- 


THE  CAMERA. 


49 


vided  with  hinges,  which  admit  of  their  being  bent  over ;  the  Ameri- 
can plan,  where  the  shutter  can  be  removed  entirely,  is  preferable. 


Fig.  24. 


Fig.  25. 


Fig.  26. 


In  the  bottom  of  the  holder  a  little  cavity  is  placed,  made  water- 
tight with  pitch,  to  collect  the  silver  drippings.  Such  a  holder,  unless 
it  is  carefully  wiped  every  time  it  has 
been  used,  is  liable  to  get  spoiled  by  the 
silver  solution  entering  the  wood.  The 
solution  decomposes  in  the  wood,  and 
the  products  of  decomposition  are  by 
capillary  attraction  carried  to  the  col- 
lodion film,  where  they  cause  moss-like 
spots.  The  author,  to  avoid  this,  places 
the  lower  part  of  the  plate-holder  for 
five  minutes  in  melted  paraffin.  This 
preserves  them  for  years  just  as  good  as 
asphalt,  with  which  plate-holders  are 
often  coated.  It  has  also  been  recom- 
mended to  paint  the  corners  with  nega- 
tive varnish.  Such  a  paint,  however, 
would  have  to  be  repeated  monthly. 

The  sizes  of  the  holders  vary  consider- 
ably. In  order  to  place  plates  of  differ- 
ent sizes  in  the  holder,  they  are  fur- 
nished with  inserting  frames  or  "  kits," 
which  are  provided  with  silver  wire 
corners  on  which  the  plates  rest. 

I  must  again  express  my  preference 
for  the  American  boxes.    The  holders 

in  them  are  supplied  with  improved  glass  corners,  which  are  imper- 

4 


50 


THE  PRACTICE  OF  PHOTOGRAPHY. 


vious  to  all  action  of  the  solution.   Moreover,  they  are  made  of  such 

a  shape  (see  Figs.  25  and  26)  that 
they  bind  the  wood  frames  together 
so  that  it  is  impossible  for  the  solu- 
tion to  get  to  the  wood  at  all.  An- 
other advantage  is  the  reversible  cor- 
ner (Fig.  26),  which  is  familiar  to  all 
my  American  readers  and  need  not 
be  described  here.  These  corners  are 
far  preferable  to  the  silver  wires.  In 
place  of  these  kits  Mr.  Benecke,  in 
St.  Louis,  takes  two  glass  rulers,  1 1 
(Fig.  27)  which  he  places  into  the 
plate-holder,  and  on  which  a  plate  of  any  size  can  be  put.  Instead 
of  placing  the  plates  flat  on  the  rulers,  the  latter  may  be  provided 
with  glass  ledges,  which  are  cemented  to  the  under  side  with  shellac, 
and  the  plates  rest  on  these  ledges. 

Then  there  are  the  sliding  holders,  by  which  two,  three,  or  more 
pictures  can  be  taken  on  the  same  plate.    On  a  broad  board,  L,  L 

(Fig.  28),  the  holder  moves 
in  a  groove  in  a  horizontal 
direction.  Three  points,  /, 
/,/,  which  catch  with  springs 
in  notches,  serve  to  keep  the 
plate  in  a  fixed  position. 
The  so-called  "  carte  de 
visite  camera"  is  so  con- 
structed. 

For  beginners  it  may  be 
necessary  to  call  attention 
to  the  fact  that  the  camera 
must  not  be  moved  while  the  ground-glass  is  removed,  and  the  plate- 
holder  put  in  its  place,  and  that  the  shutter  must  not  be  pulled  until 
the  holder  is  in  its  place.  When  all  this  has  been  done  the  cover 
is  removed  from  the  object-glass,  but  without  shaking  the  camera. 

Alluding  to  the  American  boxes  again,  Fig.  29  represents  another 
kind  of  sliding  box,  and  is  known  in  the  American  Optical  Com- 
pany's catalogue  as  the  "  Imperial "  box.  In  it  the  frame  holding 
the  plate-holder  is  made  to  slide  laterally  on  a  platform,  which  plat- 
form again  may  be  moved  vertically,  proper  catches  being  furnished 
to  fasten  both  in  position.    In  this  way  the  plate  is  moved  over  the 


JP 

I 

Fig. 28. 


THE  CAMERA. 


51 


field  of  the  lens,  allowing  the  operator  to  take  several  positions  on  one 
plate  and  even  to  change  the  sizes.  Internal  diaphragms  are  supplied 
to  effect  the  changes  in  size. 


Fig.  29. 


SECTION  III. 


USE  AND  CONSTRUCTION  OF  THE  CAMERA-TUBE. 

The  objective  consists  of  a  tube  containing  either  single  or  com- 
pound lenses  and  stops.  The  size  of  the  tube  depends  on  the  size  of 
the  lenses,  the  distance  which  they  require  to  be  apart,  and  the  posi- 
tion of  the  stops. 

Fig.  30  shows  a  very  general  mode  of  mounting.  It  represents  a 
Busch  portrait  objective  with  separate  central  stops,  D,  D1  which  are 
placed  in  the  slit  at  X;  the  flange,  FlG.  30. 

R,  is  screwed  to  the  front  of  the  cam- 
era-box. The  back  lens  is  at  H, 
and  the  front  lens  at  r.  With  the 
cap,  G,  the  lens  is  covered  or  uncov- 
ered. By  the  rack  and  pinion  move- 
ment, T,  the  fine  adjustment  in  fo- 
cussing is  made.  The  front  piece, 
which  is  screwed  on  at  r,  serves  not 
only  for  carrying  the  cover,  but  ex-  H 
eludes  also  side-light.  The  fault  of 
this  construction  is  the  detached  stops, 
which  easily  get  lost. 


52 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Fig.  31  represents  a  landscape  tube,  by  Ross,  without  cover.  The 
lens  is  placed  at  H;  the  stops  are  permanently  fixed  and  consist  simply 
of  a  disk,  8,  with  different  sized  apertures.    By  turning  the  same,  the 

dimensions  of  the  stop  are  easily  changed ;  a 
black  disk,  r,  with  an  opening  equal  to  the 
size  of  the  largest  stop,  closes  the  tube  in 
front. 

There  are  other  tubes  in  the  market, 
where  the  front  lens  can  be  used  as  a  land- 
scape lens.  To  this  class  belong  the  "  cone  " 
objectives,  as  shown  in  Fig.  32.  The  back 
lens,  if,  is  as  large  as  the  front  lens.  This 
lens  has  a  movable  mounting,  and  can 
either  be  entirely  drawn  out  or  brought  more  or  less  closely  to  the 
other  lenses,  to  lengthen  and  shorten  the  focus.  The  stops  consist -of 
rings,  which  are  placed  inside  the  tube  at  D,  the  front  part,  C,  having 
been  previously  removed.  This  front  part,  by  being  screwed  in  a  re- 
versed position  to  the  mounting,  forms,  when  all  the  other  parts  are 
removed,  a  landscape  lens  at  D,  with  stops  and  cover. 


Fig.  32. 


The  inside  of  the  tubes  should  be  perfectly  black.  When  these 
surfaces  reflect  light,  we  will  have  spots  on  the  plate  at  once.  The 
tubes  are  generally  screwed  to  separate  boards  or  fronts,  which  are 
easily  detached  from  or  placed  on  the  camera. 

For  the  purpose  of  exact  adjustment  of  focus,  the  stop  with  the 
largest  opening  is  generally  used.  Only  a  part  of  the  picture  be- 
comes sharp,  and  to  remedy  this,  stops  with  smaller  openings  are  in- 
troduced after  the  focussing  has  been  done.  When  we  wish  to  extend 
the  sharpness  as  far  as  possible  to  the  margin  of  the  plate,  we  use  a 


THE  CAMERA. 


53 


very  small  stop.  To  see  the  image  on  the  ground-glass  more  dis- 
tinctly, a  cloth,  which  is  thrown  over  the  head,  is  of  advantage.  A 
focussing-glass  enables  the  operator  to  focus  with  much  more  certainty. 
To  what  degree  of  fineness  the  ground-glass  has  been  ground  is  of 
much  importance,  for  all  imperfectly  ground  glass  is  frequently  a 
source  of  error.  Focussing  is  much  easier  with  an  objective  giving 
fine  illumination  and  in  clear  weather.  In  cloudy  weather,  and  with 
lenses  that  do  not  have  much  light,  it  is  sometimes  rather  difiicult. 

A  precautionary  measure,  which,  particularly  in  bright  weather, 
should  be  observed,  is  the  exclusion  of  all  extraneous  light  from  the 
objective.  Every  objective  acts  not  only  as  a  lens,  but  also  as  a  win- 
dow, and  admits  a  great  deal  of  diffused  light,  and  this  causes  either 
fogging  of  the  whole  plate  or  interferes  with  the  brilliancy  of  the  pic- 
ture. This  diffused  light  is  easily  discovered  by  placing  the  head 
under  the  focussing-cloth,  the  ground-glass  having  previously  been  re- 
moved. The  camera,  with  lenses  of  large  opening,  will  appear  very 
light.    To  exclude  this  foreign  light  a  box  (Fig.  33)  is  used  which 


Fig.  33. 


surrounds  the  objective,  and  has  only  an  opening  in  front,  which  can 
be  opened  and  closed  by  a  lid,  m. 

Claudet  and  Bingham  place  the  whole  apparatus  in  a  kind  of  tent 
which  moves  on  rollers.    The  arrangement  appears  very  clumsy* 


54 


THE  PRACTICE  OF  PHOTOGRAPHY. 


CHAPTER  III. 

DESCRIPTION  OF  PHOTOGRAPHIC  OBJECTIVES  (TUBES)  AND  LENSES. 

The  form  of  lenses  which  are  used  in  the  optical  department  of 
photography  will  be  explained  by  the  following  figures. 


Fig.  34. 

1  2  3  4  5  6 


Numbers  1,  2,  and  3,  are  thicker  in  the  centre  than  on  the  margin. 
They  are  called  convex  lenses.  Numbers  4,  5,  and  6,  are  thinner  in 
the  centre  than  on  the  margin,  and  are  called  concave  or  dispersing 
lenses.  We  distinguish  biconvex  (No.  1),  plano-convex  (No.  2), 
concavo-convex  (No.  3),  also  biconcave  (No.  4),  plano-concave  (No.  5), 
and  concavo-convex  (No.  6).  The  connecting  lines  of  the  centres  of 
the  spherical  surfaces,  which  form  the  surfaces  of  the  lenses,  are  the 
axis  of  the  lens.  Any  plane  which  is  placed  through  the  axis  of  the 
lens,  is  called  a  main  section. 

The  collecting  lenses  have,  within  certain  limits,  the  faculty  of  col- 
lecting to  a  point  the  rays  which  proceed  from  a  point,  provided  that 
these  points  are  situated  on  the  axis  or  near  it,  and  provided  that  the 
angle  which  the  rays  form  with  the  axis  is  not  too  large.  When, 
under  these  conditions,  a  bundle  of  rays,  parallel  to  the  axis  of  the 
lens,  falls  on  a  lens,  the  rays  will  be  united  in  a  point  back  of  the  lens, 
and  this  point  is  called  the  focus,  and  the  distance  between  the  focus 
and  the  lens  is  called  the  focal  distance.  The  rays  which  proceed 
from  a  point  on  the  axis  or  near  to  it,  are  also  united  in  a  point  back 
of  the  lens,  and  it  is  easy  to  calculate  its  distance  from  the  lens.  If, 
for  instance,  the  focus  is  =  P,  the  distance  of  the  point  of  light  =  a, 
and  the  distance  of  its  image  =  x,  it  follows  that — 

±-    =    J-  JL 

x  P  a 


X 


ap 
a^P 


DESCRIPTION  OF  PHOTOGRAPHIC  OBJECTIVES.  55 


For  instance,  a  lens  has  a  focal  length  of  10  inches  and  is  120  inches 
distant  from  an  object,  then — 

a  =  120  inches,  P  =  10  inches; 

hence — 

_ap_  =  120  X  10  =  1200  =  10>9  incheg; 
a— P       120  —  10  110 

hence  #  is  i.  e.,  the  distance  of  the  image  from  the  lens  =  10.9  inches. 
When  the  distance,  a,  is  greater  than  100  times  the  focal  length,  the 
image  and  the  focus  will  nearly  coincide. 

When  we  direct  a  lens  to  very  distant  objects,  we  will  get  in  the 
focus  of  the  lens  a  small  reversed  image  of  the  object. 

When  the  object  is  brought  nearer  to  the  lens,  the  image  will  ap- 
pear further  removed  from  the  lens.  The  exact  spot  is  easily  found 
by  construction  and  calculation. 


When  we  take  the  lance,  A,  we  will  find  that  all  the  rays  proceed- 
ing from  it,  which  travel  parallel  to  the  axis,  will  pass  through  the 
point,  P.  The  rays  which  pass  through  the  optical  centre,  O,  of  the 
lens  do  not  change  their  course.  The  point  where  the  rays  proceed- 
ing from  a  or  b  cross  each  other  determines  the  location  of  the  image 
a!,  b'.  When  lens  and  object  are  parallel  to  one  another,  the  image 
will  also  be  parallel.  When  the  object  is  inclined  to  the  lens,  the 
image  will  also  be  inclined,  but  in  a  reversed  position. 

These  circumstances  must  be  well  observed  in  focussing  with  the 
camera  obscura.  The  lines  «,  o,  and  b,  o,  which  pass  through  the 
optical  centre  of  the  lens  are  called  side  axes  in  regard  to  the  points 
a  and  b.  All  objects,  the  distance  of  which  is  more  than  a  hundred- 
fold the  length  of  the  focus,  will  form  their  image  in  the  focus  of  the 
lens.    When  we  move  the  lens  closer  to  the  object,  the  image  will 


56 


THE  PRACTICE  OF  PHOTOGRAPHY. 


move  out  of  the  focus,  and  when  we  move  the  lens  still  closer,  and  to 
within  twice  the  length  of  the  focus,  the  image  will  also  be  removed 
twice  the  length  of  the  focus  from  the  lens  or  object,  and  the  image 
will  be  equidistant  from  the  lens  in  opposite  directions.  When  we  go 
still  closer,  the  image  will  remove  still  further  from  the  lens,  or  more 
than  twice  the  focal  distance,  and  more  than  the  distance  of  the  object 
itself.  The  size  of  the  picture  depends  on  its  distance  from  the  lens. 
When  the  same  is  =  x  the  distance  of  the  object  =  a  its  size  =  G 
then  the  size  of  the  picture  will  be 


Hence  the  image  will  become  larger  as  we  approach  closer  to  the  object. 
Hence,  also,  we  can  make  larger  or  smaller  pictures  of  the  same 
object  by  bringing  the  optical  apparatus  closer  to,  or  by  removing  it 
further  from,  the  same. 

When  the  object  is  removed  further  than  twice  the  focal  length  of 
the  lens,  its  image  will  be  less  than  the  "  natural  size."  When  the 
distance  of  both  is  equal,  or  the  object  is  twice  as  far  removed  from 
the  ground-glass  as  the  focal  length,  then  the  image  will  be  of  equal 
size  with  the  object.  This  fact  is  important  in  copying  when  a  copy  is 
to  be  made  of  the  same  size  as  the  original.  The  camera  has  to  be 
drawn  out  to  equal  the  distance  of  the  object.  When  the  object  is 
moved  still  closer,  we  will  get  magnified  pictures. 

We  can,  therefore,  with  any  lens,  make  larger  or  smaller  pictures 
of  the  same  object,  and  it  would  appear  as  if  we  could  with  a  lens 
take  pictures  of  any  size  to  suit  our  pleasure.  This,  however,  is  not 
the  case,  as  a  lens,  similar  to  our  eye,  can  only  take  in  a  limited  field 
of  view  at  one  time. 

When  we  close  one  eye  we  overlook  with  the  other  a  field  of  90° 
circumference  of  angle,  but  we  must  turn  the  eye  a  little.  So,  also, 
every  lens  takes  in  a  limited  field  only,  which  is  called  its  field  of 
view.  When  we  move  a  photographic  apparatus  far  away  from  the 
model,  the  whole  figure,  of  a  person,  for  instance,  will  appear  in  the 
picture.  When  the  apparatus  is  moved  closer,  the  proportions  be- 
come larger ;  we  no  longer  see  the  whole  figure,  but  only  three-fourths 
of  it ;  and  when  we  go  still  nearer,  the  head  and  chest  only  will  ap- 
pear. > 

Large  objects,  when  they  are  wanted  entire  in  the  picture,  should 
be  far  removed  from  the  camera.  But  of  such  objects  only  small 
pictures  can  be  made. 

With  the  increase  in  the  length  of  the  focus,  the  distance  of  the 


SPHERICAL  ABERRATION. 


57 


object  from  the  lens  remaining  the  same,  the  size  of  the  picture  will 
increase,  and  hence  we  select  for  large  pictures  lenses  of  long  focus. 
When  a  is  the  distance  of  the  object,  G  its  size,j?  the  length  of  focus, 
x  the  distance  of  the  picture,  then  the  size  of  the  picture  is  B — 

B       =       G  JS- 
a — p 

When  the  distance  is  very  great,  then — 

B       =       Q  t 
a 

i.  e.,  the  sizes  of  the  pictures  are  proportioned  as  the  focal  lengths. 

A  lens  of  7  inches  focus  is  placed  opposite  to  a  person  5  feet  high 
at  a  distance  of  8  feet,  then  the  size  of  the  picture — 

5  feet  X  7  inches       60  inches  X  7  inches 
B  =         8fert         =         96  inches         =  4»  inches' 

The  field  of  view  of  a  long-focus  lens  is,  when  the  proportions  of 
the  radii  are  equal,  no  larger  than  that  of  a  short-focus  lens. 

The  production  of  pictures  by  a  lens  proceeds  only  under  certain 
conditions  in  a  regular  way,  which  conditions  have  already  been  in- 
dicated above,  and  which  become  still  more  easily  understood  by  the 
mathematical  development  which  is  given  with  it. 

1.  That  the  rays  strike  near  the  axis. 

2.  That  they  form  only  a  small  angle  with  the  axis. 

3.  That  they  are  monochromatic,  or  that  they  all  possess  the  same 
index  of  refraction. 

These  conditions  can  easily  be  maintained  in  telescopic  or  micro- 
scopic lenses,  but  it  is  much  more  difficult  with  a  photographic  lens. 
In  the  latter  the  rays  form  very  often  a  considerable  angle,  sometimes 
as  large  as  45°,  and  this  gives  rise  to  a  whole  line  of  errors,  which 
only  partially  can  be  overcome  by  optical  means.  To  these  errors 
belong — 


1.  SPHERICAL  ABERRATION. 


When  a  single  lens  (a  so-called  landscape  lens)  is  attached  to  a 
camera,  and  when  we  remove  all  the  stops,  we  cannot  obtain  on  the 
ground-glass  a  picture  which  can  be  called  absolutely  sharp,  for  such 
will  always  show  blurred  and  ill-defined  outlines.  The  picture,  how- 
ever, will  become  instantly  sharp  when  we  cover  the  front  of  a  lens 
with  a  disk  in  the  centre  of  which  a  hole  has  been  cut,  or  in  other 


58 


THE  PRACTICE  OF  PHOTOGRAPHY. 


words,  a  stop.  The  cause  of  this  want  of  sharpness  is  the  uneqal  re- 
fraction of  the  marginal  rays  as  compared  with  those  of  the  centre. 
The  margin  of  the  lens  is,  so  to  speak,  a  prism  with  a  much  stronger 
refracting  angle  than  the  centre.  As  the  dispersion  which  the  rays 
suffer  increases  with  the  refracting  angle  of  the  prism,  it  follows  that 
the  marginal  rays  will  intersect  the  axis  nearer  to  the  lens  than  the 
central  rays. 

The  focus  of  the  marginal  rays  will,  for  instance,  be  in  fz,  while  the 
focus  of  the  central  rays  will  be  in/1  (Fig.  36). 


Fig.  36. 


Hence,  if  the  ground-glass  has  been  placed  at  f1,  the  marginal 
rays,  which  have  intersected  the  axis  at  /3,  will  form  a  circle  of  dis- 
persion. The  diameter  of  this  circle  is  called  the  transversal  or 
lateral  aberration.  It  is  easily  understood  that  this  must  be  different 
in  two  lenses  of  equal  opening  and  different  focal  length,  and  it  must 
be  the  larger,  the  shorter  (with  the  same  opening)  the  focal  length  is. 
And  it  is  also  easily  understood  that  with  two  lenses  of  equal  focal 
length  and  different  opening,  the  transverse  aberration  will  be  largest 
with  the  largest  opening. 

2.  CHROMATIC  ABERRATION  OR  DISPERSION  OF  COLOR. 

The  white  light  suffers  in  its  passage  through  refracting  mediums, 
not  only  by  the  refraction,  but  also  by  the  dispersion  of  color,  the 
cause  of  which  is  that  the  apparently  monochromatic  white  light 
consists  of  rays  of  different  quality,  which  partly  distinguish  them- 
selves by  their  different  effects  on  the  retina  and  chemicals,  and 
partly  by  their  different  refractions.  Red  has  the  least  refraction ; 
violet  the  greatest.  The  dispersion  of  color  is  most  beautiful  in  the 
passage  of  white  light  through  a  prism,  and  then  it  gives  rise  to  a 
colored  band — the  spectrum — in  which  the  seven  principal  colors, 
violet,  indigo,  blue,  green,  yellow,  orange,  red,  are  distinguished.  As 
a  lens,  however,  is  analogous  to  a  system  of  prisms,  such  a  dispersion 
of  color  must  necessarily  also  take  place  in  the  passage  of  white 


f 


CURVE  OF  THE  SURFACE  OF  THE  PICTURE. 


59 


light  through  a  lens,  and  as  violet  light  is  more  refrangible  than  red, 
it  follows  that  the  violet  rays  will  intersect  the  axis  closer  to  the  lens 
(after  having  passed  through  it)  than  the  red. 

Hence,  when  a  bundle  of  parallel  rays  of  white  light  passes 


Fig.  37. 


through  a  lens,  the  rays  will  not,  after  having  been  refracted,  be 
united  in  a  single  point,  but  will,  according  to  their  different  refran- 
gibility,  be  placed  at  different  distances  from  the  lens  on  the  axis  of 
the  same.  The  violet  ones  being  the  nearest  to  the  lens,  the  red  ones 
the  farthest,  and  instead  of  having  a  single  point,  the  focus,  which 
would  result  with  the  employment  of  a  monochromatic  light,  we  will 
have  a  line  of  differently  colored  foci.    (See  Fig.  37.) 

This  error  is  overcome  by  the  employment  of  two  lenses,  which  are 
made  of  different  kinds  of  glass  (crown  and  flint).  Nearly  every 
photographic  lens  is  made  of  these  two  kinds  of  glass ;  but  even  with 
one  kind  of  glass,  by  suitably  selected  forms  of  lenses,  the  chromatic 
aberration  can  be  tolerably  well  avoided,  as  is  the  case  with  the 
Zentmayer  lens.  With  a  good  lens  the  focus  of  the  indigo  blue  and 
yellow  rays  should  coincide ;  if  this  should  not  be  the  case  the  image 
of  the  chemically  active  rays  would  fall  in  a  different  plane  from  the 
visible  image,  the  picture  will  lack  sharpness  in  spite  of  exact  focus- 
sing. It  is  said  such  a  lens  has  a  chemical  focus ;  further  on  we  will 
state  how  a  lens  is  tested  for  chemical  focus. 


CURVE  OF  THE  SURFACE  OF  THE  PICTURE. 

When  a  camera  with  any  kind  of  an  aplanatic  lens  is  sharply 
focussed  on  an  object,  it  will  be  noticed  that  it  is  not  possible  to  get 
all  the  different  parts  of  the  picture  sharply  defined  on  the  ground- 
glass  at  the  same  time.  It  is  either  sharp  at  the  margin  and  poorly 
defined  in  the  centre,  or  vice  versa.  This  error  is  not  caused  by  spheri- 
,  cal  aberration,  for  it  occurs  with  all  perfectly  aplanatic  lenses — that  is, 


60 


THE  PRACTICE  OF  PHOTOGRAPHY. 


lenses  which  have  been  corrected  for  spherical  aberration ;  but  the 
cause  of  it  is  the  curve  of  the  image. 

The  picture  does  not  lie  on  a  plane  like  the  ground-glass  but  on  a 
more  or  less  curved  surface,  and  by  moving  the  ground-glass,  only 
that  part  of  the  picture  will  appear  sharp  which  touches  or  intersects 
the  ground-glass.  The  arrow  in  Fig.  38  represents  such  a  picture. 
When  the  ground-glass  is  placed  at  a,  a,  only  the  central  part  will 
appear  sharp.  When  we  place  the  ground-glass  at  b,  6,  only  the 
points  of  the  arro  w  will  appear  well  defined. 


Fig.  38. 


These  errors  are  avoided  by  suitable  curves  in  the  lenses,  by  com- 
binations of  lenses,  and  by  stops. 


DISTORTION. 

When  we  focus,  with  a  single  lens  with  front  stops,  sharply  on  a 
square,  A  (Fig.  39),  the  resulting  picture  will  not  appear  as  a  square, 
but  with  curved  sides,  almost  as  a  barrel,  B.  The  lines  are  curved 
outwards.  When  we  substitute  a  lens  with  the  stop  in  the  rear,  the 
curves  will  be  reversed,  as  in  C. 

This  is  the  case  with  all  single  lenses,  but  not  always  to  the  same 
extent.  It  is  based  on  the  fact  that  the  marginal  rays  of  the  field  of 
view  strike  the  lens  under  a  larger  angle  than  the  central  rays,  and 
consequently  suffer  a  greater  refraction. 

But  in  this  refraction,  according  to  the  position  of  the  stops,  the 
marginal  rays  are  either  brought  nearer  to  the  centre  of  the  field  of 
view,  as  is  the  case  with  a  front  stop,  or  they  are  removed  from  it,  as 
is  the  case  when  the  stop  is  placed  behind  the  lens. 

This  distortion  becomes  more  prominent  with  the  increase  in  the 


DISTORTION. 


61 


size  of  the  field  of  view.  It  is  particularly  annoying  in  copying 
drawings,  or  taking  architectural  views.  When  single  lenses  are 
used  for  this  purpose,  the  central  part  only  can  be  employed.  The 
distortion  is  dependent  on  the  form  of  the  lens.    Amongst  all  the 


-7 


simple  forms  of  lenses,  the  meniscus  lens,  when  its  concave  side  is 
turned  towards  the  object,  shows  it  the  least.  It  increases  rapidly 
with  a  plano-convex  lens,  the  plane  side  turned  towards  the  object, 
and  still  more  so  with  a  biconvex  lens.  With  single  lenses  the  distor- 
tion can  be  reduced  to  a  mini- 


FlG.  40. 

B 


mum  by  giving  the  proper 
form  to  the  glass,  but  it  never 
can  be  avoided  entirely.  This 
is  only  possible  by  a  combina- 
tion of  lenses  with  so-called 
central  stops.  Imagine  two 
lenses,  A,  B,  at  a  certain  dis- 
tance from  one  another,  and 
between  the  two,  in  the  centre, 
the  stop,  D.  In  regard  to  the 
front  lens  this  arrangement 
will  act  like  a  back-stop,  and 
will  cause  the  distortion  no- 
ticed at  C  (Fig.  39),  while  with 
regard  to  the  second  lens,  it 
will  act  like  a  front-stop,  and 
cause  distortion  similar  to  B. 

But  as  both  distortions  are  in  opposite  directions,  they  will  balance 
each  other,  and  the  result  will  be  a  correct  image  like  A. 

Such  double  objectives  with  central  stops  are  the  Globe,  Zentmayer, 
Ross  Doublet,  and  the  new  Aplanatic  lenses  by  Steinheil. 


62 


THE   PRACTICE  OF  PHOTOGRAPHY. 


The  portrait  tubes  of  Petzval  are  similarly  constructed,  but  as  the 
lenses  are  very  unequal,  a  little  distortion  remains. 

ANGLE  OF  VIEW,  ACTINIC  POWER,  AND  DEPTH  OF  FOCUS  OF  A  LENS. 

By  the  term  that  a  lens  has  great  actinic  power,  we  mean  its  capa- 
bility of  giving  a  more  or  less  bright  picture.  This  depends — 1,  on 
the  surface  of  the  lens  ;  2,  on  its  focal  length ;  3,  on  the  loss  by  re- 
flection and  absorption  which  light  suffers  in  its  transit  through  the 
body  of  the  glass. 

The  larger  the  surface  of  a  lens  the  greater  will  be  the  quantity  of 
light  which  it  is  capable  of  receiving.  However,  the  surface  contents 
are  proportioned  to  the  square  of  the  diameter,  or,  as  it  is  generally 
called,  the  opening.  Hence,  the  amount  of  light  of  two  lenses  will 
be  proportioned,  other  things  being  equal,  as  the  squares  of  their 
openings. 

When  the  focal  distances  of  the  lenses  are  different,  they  will  give 
of  the  same  subject  pictures  of  different  size.  When,  for  instance,  a 
lens  of  6  inches  focus  gives  of  a  man  a  picture  of  3  inches,  then  a  lens 
of  12  inches  focus  will  represent  a  man  as  6  inches  high  in  the  picture. 
The  quantity  of  light  which  proceeds  from  the  subject  and  falls  on 
the  lenses  is  necessarily  the  same,  provided  the  openings  are  equal. 
But  with  increased  size  of  the  picture  the  quantity  of  light  is  spread 
over  a  larger  surface.  When  the  same  quantity  of  light  is  distributed 
over  a  surface  of  two  or  four  square  inches,  then  the  quantity  of  light 
on  a  square  inch  of  the  latter  surface  will  only  be  half  as  great  as 
on  the  former. 

But  the  surface  contents  of  two  similar  figures  are  proportioned  as 
the  squares  of  similar  located  lines — for  instance,  as  the  squares  of 
their  heights.  But  as  the  size  of  a  figure  in  the  picture  is  proportioned 
to  the  focal  length  of  a  lens,  it  follows  that  the  surface  contents 
of  the  same  are  as  the  squares  of  the  foci,  and  as  the  amount  of  light 
is  just  the  reverse  of  their  surface  contents,  it  follows  further :  the 
amount  of  light  of  two  lenses  is  proportioned  as  the  inverse  ratio  of  the 
squares  of  their  foei.  Opening  and  focus,  are,  hence,  the  main  ele- 
ments forjudging  the  amount  of  light  which  a  lens  has.  The  direct 
proportions  of  the  former,  the  indirect  proportions  of  the  latter  form 
the  criterion. 

When  we  wish  to  compare  two  lenses  in  this  respect,  we  have  to 
divide  first  the  opening  o,  by  the  focus/,  and  find  the  square  of  the 
fraction. 

The  fraction  y-  is  called  the  relative  opening.    Of  the  importance 


ANGLE  OF  VIEW,  ETC. 


63 


Fig.  41. 


of  the  same  we  shall  have  something  more  to  say  in  a  future  chapter 
on  testing  the  objective. 

This  calculation  holds  good  only  for  lenses  with  full  opening. 
When,  however,  lenses  are  used  that  have  stops,  the  size  of  the  stop 
has  to  be  substituted  for  the  opening  of  the  lens,  and  we  can  only 
compare  front-stop  with  front-stop,  and  back-stop  with  back-stop. 

The  brightness  of  a  picture,  however,  is  not  equal  in  all  its  parts. 
The  eye  alone  tells  us  that  the  brightness  of  the  image  decreases  from 
the  centre  towards  the  margin. 

This  circumstance  is  easily  explained.  Let  us  consider  the  simple 
case  of  a  lens  with  a  front 
stop.  The  diameter  of  the 
rays,  g,  g  (Fig.  41),  which 
pass  through  the  lens 
parallel  to  its  axis,  is  of 
the  same  size  as  the  open- 
ing of  the  stop  B.  The 
diameter  of  the  oblique 
bundle  of  rays  is  equal  to 
the  diameter  of  the  stop 
multiplied  with  the  cosi- 
nus  of  the  angle  of  inci- 
dence, or  equal  to  B  cos. 

x,  or,  for  instance,  for  an  angle  of  60°  =  ^  B,  and  as  the  brightness 
is  proportioned  as  the  square  of  the  opening,  the  brightness  of  centre 
and  margin  will  be  proportioned  as  1  to  4. 

With  increased  obliquity  of  the  rays  towards  the  lens  the  bright- 
ness of  the  margin  of  the  picture  will  correspondingly  decrease,  and 
this  is  the  reason  why  it  becomes  so  prominent  in  wide-augled  lenses. 

To  this  must  be  added,  that  rays  falling  obliquely  on  a  lens  lose  a 
considerable  amount  of  light  by  reflection  from  the  surface  of  the 
glass,  and  that  this  loss  of  light  increases  with  the  increase  of  oblique- 
ness. 

This  causes,  in  short  exposures,  the  apparent  under-exposure  of  the 
margin.  Sometimes  this  is  of  advantage,  when  it  is  desirable  to  con- 
centrate the  main  light  on  a  characteristic  object  located  in  the 
centre  of  the  plate,  as,  for  instance,  on  the  head  in  portraiture.  It  be- 
comes very  annoying  in  pictures  of  buildings,  landscapes,  and  draw- 
ings, however. 

The  above-mentioned  reflections  from  the  surface  of  the  glass  mani- 
fest themselves  otherwise  unpleasantly  as  they  produce  the  so-called 
light  spot  (ghost)  and  secondary  pictures. 


64 


THE  PRACTICE  OP  PHOTOGRAPHY. 


When  light  falls  on  a  lens,  a  part  of  it  is  reflected  from  the  sur- 
face, another  part  enters  the  lens,  passes  through  it,  and  on  the  back 
surface  another  reflection  takes  place.  The  reflected  rays  strike  the 
front  surface,  are  again  thrown  back,  and  are  now  by  the  back  sur- 
face partly  reflected,  partly  refracted,  and  thus  a  secondary  picture 
is  formed,  which  of  course  is  very  feeble  and  of  little  effect  in  short 
exposure,  but  which  will  make  itself  felt  and  seen  with  a  long  one. 
The  focus  of  the  secondary  picture  is  dependent  on  the  curve  of  the 
lens.  Generally  it  is  quite  different  from  the  principal  focus  of  the 
lens,  and  the  consequence  is  that  the  secondary  picture  does  not  ap- 
pear sharp  on  the  ground-glass  when  the  lens  is  in  focus,  but  only  as 
a  bright  spot  next  to  the  bright  object.  With  an  increased  curve  of 
the  surface  of  the  lens  the  reflection  will  increase,  and  also  the  bright- 
ness of  the  secondary  picture.  By  reducing  the  size  of  the  stop,  the 
sharpness  of  the  secondary  image  increases  (particularly  in  such  lenses 
as  the  Globe  lens),  and  when  the  front  lens  is  struck  by  direct  sun- 
light, or  is  turned  to  the  bright  blue  sky. 

When  the  focus  of  the  secondary  picture  is  infinite,  then  it  will  ap- 
pear as  an  image  of  the  stop,  and  will  be  distinctly  noticeable  as  a 
bright  spot  in  the  centre  of  the  picture.  When,  in  such  a.  case,  we 
move  the  stop  forward,  the  spot  will  become  smaller  and  better  defined, 
and  the  reverse  takes  place  when  we  remove  the  stop  backwards.  The 
latter  proceeding  enables  us  sometimes  to  avoid  or  to  reduce  its  evil 
effects. 

We  have  still  to  explain  what  we  mean  by  the  expression,  the  field 
of  view  of  a  lens. 

When  a  lens  is  screwed  to  a  large  camera  and  focussed  on  a  distant 
object,  we  will  notice  on  the  ground-glass  a  bright  circular  disk.  The 
diameter  of  the  disk  is  independent  of  the  size  of  the  stop.  When  we 
compare  lenses  of  unequal  construction  and  equal  focus,  we  will  find 
that  this  similar  image  is  of  very  different  size.  The  angle,  under 
which  this  picture  is  seen  from  the  optical  centre  of  the  objective,  is 
called  the  field  of  view  of  the  lens. 

When  a  b  (Fig.  42)  is  the  diameter  of  the  round  picture,  and  c  d 
equal  to  the  focal  length,  then  is  the  angle,  a,  d,  b,  the  field  of  view. 

Of  the  round  picture  only  a  portion  will  appear  sharp — namely, 
the  central  part,  and  the  sharpness  will  extend  further  towards  the 
margin  as  the  size  of  the  stops  decreases. 

The  practical  size  of  the  picture  is,  hence,  for  a  given  stop,  always 
smaller  than  the  field  of  view.  This  size,  as  well  as  the  size  of  the 
field  of  view,  is  also  determined  by  the  angle,  d,  formed  by  lines  drawn 
to  two  diametrically  opposite  points  of  sufficient  distinctness. 


ANGLE  OF  VIEW,  ETC. 


65 


The  term  depth  of  focus  denotes  the  capability  of  giving  in  the  same 
plane  an  image  of  objects  near  and  far.  With  objects  which  are  fur- 
ther removed  from  the  camera  than  fifty  times  the  length  of  the  focus 
of  the  lens,  this  is,  eo  ipso,  the  case;  the  images  in  this  case  are  placed 
in  the  focus  of  the  lens,  the  image  of  nearer  objects  is  further  removed 


Fig.  42. 

d 


from  the  lens.  If  therefore  objects  which  are  very  near  and  very  far 
from  the  lens  are  to  be  represented  at  the  same  time,  we  cannot 
focus  on  them  simultaneously  with  the  full  opening  of  the  lens.    If  we 

Fig.  43. 


focus  on  the  further  one  at  /  (Fig.  43),  the  nearer  one,  the  focus  of 
which  is  atp,  will  form  a  diffused  circle  of  the  diameter  a  b;  if  on  the 
other  hand  we  focus  on  the  nearer  one  p,  the  further  one  will  form  a 
diffused  circle  (c  d).  On  the  size  of  this  diffusion  circle  depends  the 
want  of  sharpness ;  a  b  is  evidently  smaller  than  c  d. 

It  is  therefore  better  to  foeus  on  the  distant  objects  than  on  the  nearer 
ones,  except  when  the  foreground  is  of  the  greatest  importance. 

The  want  of  sharpness  is  here  also  proportioned  as  the  square  of  the 
diame.ter  of  the  diffusion  circle.  If  we  reduce  the  diameter  of  the 
lenses  by  employing  diaphragms,  the  size  of  the  diffusion  circle  will 

5 


66 


THE  PRACTICE  OF  PHOTOGRAPHY. 


also  be  reduced,  and  hence  the  want  of  sharpness  decreases  and  in- 
creases with  the  square  of  the  diameter  of  the  lens ;  it  increases  also 
with  the  square  of  the  focus.  This  is  the  reason  why  lenses  of  very 
long  focus  can  only  be  furnished  with  relatively  small  openings.  With 
small  lenses  of,  say  6  inches  focus,  the  opening  may  be  increased  to  i 
the  focal  length  or  2  inches;  if  we  would  do  the  same  with  a  large  lens 
of,  say  24  inches  focus,  we  would  have  a  lens  of  8  inches  diameter. 
This  would  increase  the  want  of  sharpness  at  p  to  sixteen  times  as 
much  as  with  a  small  lens  of  2  inches  opening,  and  this  want  of  sharp- 
ness would  be  very  disagreeable  to  the  eye.  On  account  of  their  large 
opening,  the  portrait  object-glasses  have  the  least  depth,  while  the 
pantoscopes  have  the  most. 

DESCRIPTION  OF  PHOTOGRAPHIC  OBJECTIVES. 

We  have  explained  in  the  previous  chapter  the  shortcomings  of  our 
lenses.  We  have  demonstrated  that  these  shortcomings,  in  the  face 
of  the  exacting  demands  which  are  made  upon  a  photographic  lens, 
can  only  partially  be  overcome,  and  not  entirely  removed,  and  all  our 
photographic  lenses,  even  those  of  the. very  best  construction,  will 
leave  something  to  be  desired. 

The  qualities  expected  in  a  photographic  lens  are,  1.  A  great  amount 
of  light,  to  enable  us  to  take,  in  the  shortest  space  of  time,  the  picture 
of  a  dark  or  a  moving  object.  This  can  only  be  accomplished  by  a 
large  opening  and  short  focus.  2.  Great  sharpness  even  to  the  mar- 
gin, a  quality  that  can  only  be  secured  by  the  employment  of  small 
stops,  and  just  the  opposite  condition  to  what  is  required  in  the  first 
case.  3.  A  large  and  plain  field  of  view.  This  requires  very  oblique 
rays  of  light,  for  which  the  spherical  aberration  and  the  curvature  of 
the  picture  can  only  be  corrected  with  great  difficulty.  4.  Freedom 
from  distortion.  5.  Absence  of  chemical  focus.  6.  Equal  intensity 
of  light  over  the  whole  field  of  view.  7.  Depth,  or  equal  sharpness 
for  objects  which  are  at  unequal  distances  from  the  camera. 

All  these  conditions  can  only  be  fulfilled  with  difficulty  and  not  at 
the  same  time,  and  this  is  the  reason  why  we  have  no  universal  lens 
answering  all  purposes.    For  this  reason,  also,  we  are  compelled  to  • 
employ  different  lenses  for  different  work. 

Most  lenses  conform,  in  a  degree  sufficient  for  practical  purposes,  to 
the  condition  mentioned  under  Class  5,  but  only  partially  to  the  other 
conditions.  • 

The  portrait  objective  fulfils  condition  No.  1,  a  large  amount  of 
light,  but  the  others  only  imperfectly.    The  triplet  objective  and  the 


THE  SIMPLE  ACHROMATIC  OBJECTIVE,  ETC.  67 

Steinheil  aplanatic  lens  fulfil  condition  No.  4  (correct  drawing);  they 
excel  the  portrait  lens  in  regard  to  condition  No.  3,  the  field  of  view, 
and  No.  7,  but  are  inferior  in  regard  to  the  amount  of  light.  The 
pantoscope  and  the  Zentmayer  lens  excel  all  others  in  field  of  view 
and  depth  (No.  7) ;  are  the  equals  of  the  previous  ones  in  regard  to 
No.  4  (correctness),  but  inferior  in  the  amount  of  light.  The  Dall- 
meyer  landscape  lens  answers  the  same  conditions  as  the  Steinheil 
lens,  but  is  inferior  to  it  in  correctness  of  drawing  and  the  amount  of 
light.  The  Ross  doublet  fulfils  the  conditions  similar  to  the  latter, 
and  is  correct  in  drawing.  Depth  is  only  found  in  instruments  with 
a  small  opening.  The  most  perfect  is  the  pantoscope,  and  the  least  so 
is  the  portrait  lens.  It  is  not  to  be  wondered  that  we  find  so  many 
different  constructions  which  perform  so  well  in  one  direction  and  do 
so  little  in  another. 

To  describe  all  these  constructions  would  be  out  of  place  in  a  work 
of  this  kind.  We  will  only  refer  to  those  which  we  consider  the  most 
important  and  which  we  have  tried  practically.  The  manner  of  test- 
ing lenses  we  will  explain  further  on. 

1.  THE  SIMPLE  ACHROMATIC  OBJECTIVE,  OR  THE  SO-CALLED 
LANDSCAPE  LENS, 

This  simple  objective  is  the  oldest  photographic  lens  in  existence. 
Its  forms  are  very  different,  but  are  always  an  achromatic  combina- 
tion, consisting  of  a  pair  of  lenses  cemented  together,  and  with  a  front 
stop.  Skilled  photographers  very  often  remove  single  lenses  from  a 
system,  and  use  them  with  proper  front  stops  for  landscape  work, 
where  a  little  distortion  is  of  trifling  importance.  The  almost  plano- 
convex front  lens  of  a  portrait  combination  is  very  often  used  for  this 
purpose  by  reversing  it  and  placing  stops  in  front.  For  many  purposes 
this  is  sufficient.  There  are  many  photographers  who  make  reproduc- 
tions with  such  a  lens.  The  distortion  becomes  only  perceptible  when 
the  field  of  view  is  taken  too  large.  Within  an  angle  of  15°  it  will 
hardly  be  noticed. 

The  lenses  which  were  first  introduced  in  the  market  under  the 
name  of  landscape  lenses  had  the  following  form : 

Fig.  44,  /:  /  represents  flint-glass ;  c,  crown-glass.  The  stop,  B,  B, 
is  generally  one-fifth  of  the  focal  length  distant  from  the  lens. 

We  meet  with  this  lens  in  many  ateliers.  Besides  this  form  there 
are  many  others  which,  in  regard  to  field  of  view,  size  of  picture,  and 
correctness  of  drawing,'  yield  better  results. 

One  of  these  is  in  the  form  of  a  meniscus,  iJ,  consisting  of  a  con- 


68 


THE  PRACTICE  OF  PHOTOGRAPHY. 


cavo-convex  crown-glass  and  a  convex-concavo  flint-glass  lens ;  both 
are  cemented  together  with  Canada  balsam  similar  to  the  old  lenses. 


Fig.  44. 


c 

<  

\f/  \ 

I 

E 


fff 

1 ' 

<— 

Fig.  45. 


A  third  form,  which  gives  still  better  results,  is  Dallmeyer's  land- 
scape lens,  Fig.  45. 

This  combination  consists  of  three  lenses  cemented  together.  The 
central  one  is  made  of  flint-glass,  and  the  two  outer  ones  of  two  dif- 
ferent kinds  of  crown-glass.  The  stop  is  placed  at  about  one-tenth  of 
the  focal  length  from  the  lens.    Instead  of  several  stops,  which  can  be 

changed  according  to  the  wish  to  in- 
crease the  sharpness  towards  the  mar- 
gin of  the  field,  the  Dallmeyer  lens  is 
provided  with  a  circular  disk  with 
different-sized  holes;  the  disk  is  fast- 
ened to  the  tube. 

The  distortion  of  this  lens  is  less 
than  any  of  the  other  forms,  also  the 
curve  of  the  picture ;  both  are  favora- 
ble to  the  size  of  the  field  of  view, 
and  give  the  further  advantage  that 
with  rather  large  stops  sufficiently 
sharp  pictures  can  be  obtained.  The 
opening  of  the  smallest  stop  is  one-thirtieth  of  the  focal  length. 


2.  THE  PORTRAIT  OBJECTIVE. 

The  Landscape  objective  was,  in  the  earlier  days  of  photography, 
almost  exclusively  employed.  It  suffices  for  landscapes,  where  the 
objects  are  at  rest,  where  light  is  at  one's  disposal,  and  where  a  little 
distortion  does  not  amount  to  much.  For  this  class  of  work  the 
landscape  lens  is  employed  to  this  day.  The  opening  of  such  a  lens, 
however,  is  small,  under  the  most  favorable  circumstances  one- 


THE  SIMPLE  ACHROMATIC  OBJECTIVE,  ETC. 


69 


twentieth  of  the  focal  length,  and  the  consequence  is  a  proportionally 
small  intensity  of  light,  which  becomes  particularly  annoying  when 
we  wish  to  take  interiors,  rooms  which  are  only  partially  illuminated. 
A  person  in  the  glass-house  had  to  sit  in  front  of  such  a  lens  for 
several  minutes,  and  this  circumstance  compelled  the  early  photogra- 
phers to  place  their  models  often  in  the  open  air,  and  even  in  direct 
sunlight.  That  in  this  way  no  artistically  perfect  pictures  could  be 
made  is  self-evident,  and  it  became  soon  necessary  for  portrait  pho- 
tographers to  have  a  lens  that  would  work  with  a  large  opening,  and 
hence  have  a  large  amount  of  light. 

The  invention  of  such  a  lens  by  Petzval,  in  Vienna,  in  the  year  1841, 
was  an  event  in  photography,  as  by  it  portraiture  became  a  possi- 
bility. 

The  invention  of  these  lenses  is  no  accident,  but  the  consequence  of 
a  thorough  theoretical  calculation.    Voigtlander,  in  Vienna,  made 


the  first  lens  according  to  Petzval's  directions,  and  Martin,  in  Vienna, 
took  the  first  daguerreotype  with  short  exposure. 

This  Portrait  lens  is  a  double  objective  with  central  stop  and  two 
unequal  lenses. 

The  front  lens,  A  (Fig.  46),  consists  of  a  biconvex  crown,  and  an 
almost  plano-convex  flint-glass  lens,  which  are  cemented  together  with 
Canada  balsam. 

The  back  lens,  B,  consists  of  a  piano-meniscus  of  flint,/',  and  a 
biconvex  crown-glass  lens,  c',  which  are  separated  by  a  ring. 

Between  the  two  the  central  stop,  D,  is  placed,  which  has  to  be 
smaller  in  proportion  as  we  wish  to  push  the  sharpness  of  the  picture 
to  the  margin.  In  this  general  form,  all  the  portrait  lenses  coincide ; 
only  the  new  Dallmeyer  portrait  lens  differs  from  it  by  the  reversed 


Fig.  46. 


70 


THE  PRACTICE  OF  PHOTOGRAPHY. 


position  of  the  back  lens.  Otherwise  we  find  variations  with  different 
opticians  in  regard  to  focal  length  of  the  separate  objectives,  A  and 
B,  the  distance  and  size  of  the  same,  the  position  of  the  stops,  &c, 
which  materially  influence  the  qualities  of  the  lens. 

A  comprehensive  exhibit  of  these  differences  the  table  on  page  71 
is  intended  to  furnish,  which  contains  the  result  of  the  measurements 
which  have  been  made  in  the  celebrated  optical  establishment  of 
Herr  E.  Busch,  in  Kathenow,  with  different  portrait  objectives  of  36 
lines  diameter : 

The  effect  of  the  two  combined  glasses  is  given  in  a  great  measure 
in  the  explanation  in  the  previous  chapter  on  the  errors  of  lenses. 

The  front  lens  is  almost  entirely  aplanatic,  and  would,  if  employed 
by  itself  in  the  original  position,  yield  without  stop  a  sharp  but  much- 
curved  picture. 

The  front  lens  of  a  Voigtlander  carte  de  visite  lens  of  68  millime- 
tres diameter  will  give  a  picture  at  330  millimetres  focus.  The  addi- 
tion of  a  second  lens  produces  a  shortening  of  the  focus  and  an  in- 
crease of  light. 

In  the  above-mentioned  Voigtlander  objective,  by  adding  a  back 
lens,  the  focus  is  reduced  to  230  millimetres  and  the  intensity  of 
light,  without  taking  the  absorption  of  light  by  the  glass  into  consid- 
eration, is  increased  in  the  reversed  proportion  of  the  square  of  the 
focus — i.  e.y  in  the  proportion  of  529  : 1089,  or,  approximately,  1 :  2. 

The  more  closely  the  lenses  A  and  B  are  brought  together  the 
shorten  the  focus  will  become,  and  consequently  we  will  have  a  cor- 
responding increase  in  the  intensity  of  light.  But  we  observe  that  at 
the  same  time  the  curvature  of  the  picture  and  the  spherical  aberra- 
tion for  oblique  rays  increase. 

S"  (Fig.  46)  are  two  oblique  bundles  of  rays,  parts  of  which 
pass  completely  through  the  front  lens.  Those  parts,  however,  which, 
according  to  the  explanation  already  made,  would  cause  spherical  ab- 
erration, are  cut  off  by  the  mounting,  F,  F.  The  mounting  acts  as  a 
stop,  and  by  increasing  its  length  a  proportional  quantity  of  oblique 
rays  is  excluded.  It  is  easy  to  see  that  when  the  lenses  A  and  B  are 
far  removed  from  one  another  the  oblique  rays,  S,  S,  will  be  almost 
entirely  cut  off  by  the  mounting ;  it  follows  then  when  the  lenses  are 
far  apart  the  field  of  view  will  be  reduced  in  size. 

Consequently  the  distance  of  the  two  combinations  is  of  much  im- 
portance. In  the  commercial  lenses  which  give  much  light,  as,  for 
instance,  Mr.  Ross's  carte  stereoscopic  lenses,  and  also  his  rapid  lenses 
for  taking  children's  pictures,  the  two  combinations  are  closely  moved 
together,  and  the  picture  is  very  bright,  but  much  curved ;  when  we 


THE  SIMPLE  ACHROMATIC  OBJECTIVE,  ETC.  71 


bring  it  on  the  ground-glass  without  resorting  to  stops,  only  a  small 
portion  of  the  picture  will  appear  absolutely  sharp. 

In  the  larger  objectives,  which,  comparatively  speaking,  give  less 
light,  the  distance  between  the  two  objectives  is  much  greater,  the 
focus  is  longer,  but  the  picture  is  larger,  darker,  and  less  curved. 


00. 

O. 

I. 

IT. 

nr. 

IV. 

Front  lens. 

Equivalent  focus  in  inches, 

22.34375 

20.125 

17.9219 

15.750 

13.5469 

11.3906 

Back  lens. 

Equivalent  focus  in  inches, 

35.46875 

31.9219 

28.375 

24.822 

21.2915 

17.750 

Double  objective. 

Equivalent  focus  in  inches. 

15.250 

13.729 

12.0469 

10.6875 

9.2041 

7.6875 

Distance  of  the  two  objectives. 

Measured  from  the  highest 
points  of  the  two  exterior 
convex  surfaces,    .    .  . 

6.833 

6.180 

5.550 

4.900 

'4.375 

3.800 

Measured  from  the  mount- 

O.UoU 

o.oo  1 

4.  oyu 

4. 020 

3.350 

The  diameter  of  the  objec* 
tive  is  proportioned  to  the 
equivalent  focus  nearly  as 

1  :  5 

1:4* 

1  :  4 

1  :3* 

1  :  3 

1  :2i 

The  diameter  of  the  objec- 
tive (3  inches)  divided  by 
the  focal  length,    .    .  . 

0.1967 

0.2185 

0.2490 

0.2807 

0.3259 

0.3902 

The  squares  of  the  above 

0.0387 

0.0477 

0.0620 

0.0789 

0.1062 

0.1523 

When  the  light  of  the  sys- 
tem of  lenses,  00  is  taken 
as  I,  then  the  other  sys- 
tems will  be 

1.000 

1.232 

1.602 

2.039 

2.744 

3.935 

1 

H 

2 

2| 

4 

The  intensity  of  light  ex- 
pressed in  seconds  might 
be  expressed  in  the  follow- 
ing manner,  when  a  given 
picture,  for  instance,  a 
carte  de  visite,  should  be 
made  with  all  the  lenses 
at  once  and  all  the  stops 
being   equal,    the  time 

40 

32 

25 

20 

10 

Of  equal  importance  with  the  distance  of  the  combination  is  the 
form.  The  separation  of  the  crown  and  flint-glass  lenses  by  a  ring  is 
peculiar. 


72 


THE   PRACTICE  OF  PHOTOGRAPHY. 


The  achromatic  rays  which  have  been  refracted  by  the  front  lens 
strike  the  flint-glass  lens,  /',  and  suffer  so  much  dispersion  that  the 
rays  of  the  axial  bundle,  S,  emerge  almost  parallel,  the  oblique  rays, 
S',  S",  diverge  considerably ;  hence,  it  follows  that  for  the  axial  rays, 
the  change  in  the  distance  of  the  two  lenses,  /  and  c',  is  of  trifling 
importance  when  compared  with  the  oblique  rays. 

When  the  ring  is  too  small  the  margins  of  the  picture  will  be  defi- 
cient in  sharpness,  and  the  picture  will  be  too  much  curved. 

An  objective  which  gives  a  picture  of  great  curvature,  and  deficient 
in  sharpness  at  the  margin,  can  often  be  improved  by  changing  the 
ring  in  the  back  lens.  This  of  course  requires  great  care  and  many 
experiments. 

Fig.  47. 


C 


On  the  other  hand,  the  distance  between  the  two  lenses  has  great 
influence  on  the  achromatism  ;  the  blue  rays,  on  leaving  the  flint-glass, 
diverge  more  than  the  yellow  ones,  or  proceed  apparently  from  a 
point  nearer  to  the  second  lens,  /,  cr,  Fig.  46,  than  the  latter.  By 
increasing  the  distance  of  the  two  glasses,  or  what  is  the  same,  by 
increasing  the  size  of  the  ring,  we  increase  also  the  length  of  the  chem- 
ical focus  as  compared  with  the  optical  one. 

We  meet  with  a  peculiar  construction  of  the  back  lens  in  Dall- 
meyer's  new  objectives. 

The  form  is  approximately  the  same  as  in  the  old  objectives,  but 
the  position  is  reversed — i.  e.,  the  flint-glass  lens  is  back,  and  the 
crown-glass  lens  is  in  front ;  the  distance  of  the  two  is  variable,  as  the 
distance  between  flint  and  crown-glass  lenses  can  be  regulated  by  a 
screw  movement. 

With  larger  distance  the  marginal  rays  will  fall  on  the  lens  nearer 
to  its  centre,  where  the  dispersion  is  less ;  but  with  a  shorter  distance 
the  rays  will  strike  nearer  the  margin,  where  the  dispersion  is  greater. 
The  lens  is  so  constructed  that  in  the  latter  case  the  spherical  aberra- 
tion is  almost  entirely  removed.  When,  by  the  screw  movement,  the 
lenses  are  removed  from  each  other,  a  considerable  spherical  aberra- 
tion is  produced,  and  instead  of  one  focus,  a  number  of  focal  points, 
/,/",/",  make  their  appearance.    (See  Fig.  36,  p.  58.) 


THE  ORTHOSCOPIC  LENS. 


73 


The  ground-glass  can  be  moved  a  little  without  interfering  particu- 
larly with  the  sharpness  of  the  picture,  and  securing,  at  the  same 
time,  depth  of  focus.  Experience  has  taught  us,  however,  that  this 
supposition  is  not  entirely  admissible;  at  all  events,  the  advantages 
gained  by  this  screw  movement  are  immaterial. 

Besides  the  form,  the  size  of  the  back  lens  exercises  considerable  in- 
fluence. The  lens  is  generally  made  wider  than  the  front  lens.  This 
is  the  case  in  a  striking  manner  in  the  conical  objectives.  By  increas- 
ing the  size  of  the  back  lens  the  effectual  part  of  the  bundle  of  rays, 
S',  increases  likewise,  and  which,  with  smaller  lenses,  is  cut  off  by  the 
mounting,  F,  F.  The  consequence  is  greater  brightness  of  the  margin 
of  the  picture,  but  also,  as  has  been  shown  above,  more  spherical 
aberration  of  the  oblique  rays. 

The  portrait  objective  is  nearly  free  from  distortion. 

As  an  example  we  give  the  result  of  an  examination  of  Voigtlander's 
carte  de  visite  objective: 

Practical  field  of  view 
Diameter.  Focus.  Field  of  view.  with  full  opening. 

68.5  millimetres,     230  millimetres,     43°  50',  22°  10'. 


3.  THE  ORTHOSCOPIC  LENS. 


Fig.  48. 


For  the  copying  of  drawings,  or  for  taking  views  of  architectural 
objects,  it  is  of  advantage  to  have  an  instrument  which  will  give  as 
flat  a  field  as  possible.  The  Orthoscopic  lens,  calculated  by  Petzval, 
meets  these  requirements.  Formerly  this  lens,  besides  those  we  have 
described  above,  was  in  general  use;  now,  however,  the  Triplet  has 
generally  taken  its  place. 

The  Orthoscopic  consists  of  a  large  concavo-convex  front  lens,  A 
(Fig.  48),  with  cemented  crown  and  flint-glasses,  and  a  combination 
of  lenses,  B,  the  back  lens,  at  the  same 
time  acting  as  a  dispersing  glass.  This 
latter  combination  consists  of  a  bicon- 
cave flint  and  a  concavo-convex  crown- 
glass  lens. 

The  stops  are  generally  arranged  at 
the  back  of  the  lens.  • 

A  drawback  to  this  form  of  lens  is 
the  distortion;  the  straight  lines  are 
generally  curved  inwards:  this  circum- 
stance makes  it  less  suitable  for  the 

copying  of  drawings  and  the  taking  of  architectural  objects  than  the 
Triplet. 


74 


THE  PRACTICE  OF  PHOTOGRAPHY. 


4.  THE  TRIPLET  LENS. 


Fig.  49. 


The  Triplet  objective  owes  its  name  to  its  construction.  It  consists 
of  three  systems  of  lenses,  two  achromatic  collecting  lenses  and  a 
smaller  dispersing  lens  placed  between  them ;  the  diameter  can  be 
more  or  less  modified  by  central  stops. 

When  two  equal  collecting  lenses  are  combined  to  a  doublet,  with 
central  stops,  we  will  get  a  picture  which  has  the  advantage  over  the 
Orthoscope  of  being  free  from  distortion  and  having  greater  intensity 
of  light  than  a  single  lens  of  the  same  focal  length,  but  at  the  same 
time  the  picture  would  be  much  curved.  To  remedy  this  defect  Sut- 
ton introduced  a  concave  lens  between  them.  This  lens  acts  as  the 
dispersing  one;  it  makes  the  rays  diverge,  and  consequently  the  focus 
becomes  longer. 

The  more  converging  oblique  rays  passing  through  the  margin  of 
the  intermediate  lens,  which  latter  has  greater  dispersing  power,  will 
experience,  consequently,  a  greater  lengthening  of  the  focus  than  the 
axial  rays  which  pass  through  the  centre  of  the  lens. 

The  marked  curvature  of  the  picture  is  almost  entirely  obviated  by 
this  arrangement.    The  original  triplet  of  Sutton  was  symmetrical. 

Dallmeyer  deviates  in  many  respects 
from  Sutton's  directions,  and  his 
triplets  have  a  small  front  lens,  A 
(Fig.  49),  and  a  larger  back  lens,  B. 

The  stops,  D,  are  in  front  of  the 
middle  lens,  Z. 

The  whole  system  gives,  with  the 
full  opening,  pictures  which  are 
sharp  in  the  centre ;  as,  however,  the 
full  opening  is  proportionally  larger 
than  in  a  portrait  objective,  the  lens 
gives  not  quite  as  much  light.  To 
extend  the  sharpness  to  the  margin, 
the  use  of  stops  is  necessary. 

The  Triplet  lens  covers  a  larger 
and  flatter  field  than  most  portrait 
lenses,  and  when  correctly  construct- 
ed it  is  free  from  distortion.  The 
lens  is  frequently  employed  for  the  copying  of  drawings,  architectural 
objects,  and  landscapes. 

The  deficiency  in  light  makes  them  undesirable  for  portraiture. 
Dallmeyer  states  that  by  removing  the  middle  lens  the  tube  can  be 


Ta 


steinheil's  aplanatic  lens. 


75 


used  for  portraiture.  This  would  shorten  the  focus  considerably  and 
increase  the  intensity  of  light,  but  the  field  would  appear  very  much 
curved,  and  the  picture  would  not  be  equal  to  one  taken  with  a  com- 
mon Portrait  lens. 

Lately  Dallmeyer  and  also  Busch  'have  made  experiments  to  in- 
crease the  "light"  of  these  lenses  by  increasing  the  size  of  the  middle 
lens,  and  in  this  way  an  objective  has  been  constructed  which  retains 
the  large  and  flat  field  of  view  of  the  ordinary  triplet,  but  which  pos- 
sesses a  greater  intensity  of  light,  and  thus  approaches  nearer  to  the 
Portrait  lens.  Busch's  improved  Triplet  is  known  under  the  name  of 
the  Universal  Triplet  (so  called  because  it  is  adapted  to  so  many  dif- 
ferent purposes). 

This  Universal  Triplet,  on  account  of  its  large  field,  does  good  ser- 
vice in  taking  groups.  A  condition  for  success,  however,  is  a  good 
light. 

To  show  a  comparison  of  the  old  and  new  Triplet  lenses,  we  give 
below  the  result  of  several  experiments : 


Dian 
of 
front 
lens. 

leter 
of 
middle 
lens. 

Focus. 

Field 

of 
view. 

Size 
of 
picture. 

Relative 
size 
of 
stop. 

Remarks. 

Dallmeyer's  ) 
Triplet,  y 
No.  1,  j 

Busch's  ) 
Universal  > 
Triplet.  J 

32  m. 
64  m. 

18.5  m. 
50.5  m. 

207 
390 

70°  40' 
72° 

44°  30' 
45° 

0.027 

Full 
opening. 

Slight  distortion. 
Draws  correctly. 

The  middle  lens  is  in  the  older  Triplets  smaller  than  T\j  of  the  focal 
length,  and  in  the  Universal  larger  than  &  of  the  focal  length.  The 
Universal  cannot  be  used  without  the  middle  lens. 


5.  steinheil's  aplanatic  lens. 

We  possess,  in  the  Triplet  lens,  an  objective  which  combines,  with 
correct  drawing  properties,  a  tolerably  flat  field  and  considerable  in- 
tensity of  light ;  but  we  cannot  deny  that  these  results  are  reached  by 
a  rather  complicated  process.  The  three  lenses  consist  each  of  two 
glasses,  each  of  which  has  two  surfaces,  so  that  in  all  we  have  twelve 
surfaces,  to  be  ground  and  polished.  The  large  number  of  surfaces 
reflects  or  absorbs  a  considerable  quantity  of  light. 

Steinheil,  in  Munich,  attempted  the  construction  of  a  lens  which, 
being  simpler  in  composition,  should,  in  regard  to  its  intensity  of 
light,  flatness  of  field,  and  correctness  of  drawing,  equal  the  Triplet. 


76 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Thus  originated  the  Aplanatic  objective,  which,  in  a  remarkable 
manner,  fulfils  all  these  conditions. 

Steinheil's  Aplanatic  consists  of  two  flatly  curved  symmetrical 
lenses,  A,  B  (Fig.  40).  Each  separate  one  is  composed  of  two  ce- 
mented meniscus  lenses,  consisting,  however,  of  glasses  of  different  re- 
fracting power.  The  construction  is  the  result  of  careful  calculations 
by  Dr.  Steinheil,  which  so  far,  however,  have  not  been  published. 

The  Aplanatic  gives,  with  the  full  opening  (\  of  the  focal  length), 
a  sharp  picture  of  the  size  of  §  of  the  focal  length,  and  can,  with  good 
light,  be  used  for  portraiture,  the  same  as  the  Universal  Triplet ;  but 
it  is  slower  than  an  ordinary  portrait  combination.  What  the  lens  is 
capable  of  doing  will  be  best  explained  by  a  statement  of  the  result 
of  an  examination  by  a  committee  of  the  Photographic  Society  of 
•  Berlin. 


Diameter. 

Focus. 

Size  of 
picture 

for 
portraits. 

Land- 
scape 

Field  of 
view. 

Practical 
size  of  pic- 
ture with 
0.026  stop. 

Remarks. 

19"' 

w 

w 

J  According  to  the  statement 
\    of  price-list. 

43  m. 

296.6  m. 

6" 

65°  20' 

43°  20' 

("According  to  the  report  of 
\    the  commission. 

Steinheil  has  lately  constructed  another  wide-angled  Aplanatic  lens, 
which  has  a  lesser  light  intensity  than  the  old  Aplanatic  one,  but  a 
considerably  larger  field  of  view.  "We  have  found  that  the  Aplanatic 
may  be  comfortably  used  with  a  field  of  view  up  to  60°,  without  im- 
pairing the  sharpness.  The  Aplanatic  is  the  best  instrument  for  archi- 
tectural objects,  landscapes,  and  reproductions. 

The  latest  novelty  in  the  realm  of  wide-angled  lenses  is  Steinheil's 
wide-angled  Aplanatic  lens,  which  excels  all  other  wide-angled  lenses 
in  its  light-intensity,  although  in  this  respect  it  is  inferior  to  the  old 
one.  With  full  opening,  it  gives  pictures  which  are  sharp  up  to  an 
angle  of  80°. 

6.  THE  GLOBE  LENS  AND  THE  PANTOSCOPE. 

The  lenses  which  we  have  described  so  far,  have  only  a  moderately 
large  field,  which,  under  very  favorable  circumstances,  may  extend  to 
60°.  Such  a  field  may  be  sufficient  for  most  landscape  and  architec- 
tural purposes,  but  it  is  inadequate  when  the  photographer  has  only 
a  short  distance  between  the  lens  and  object  at  his  disposal,  a  case 
of  frequent  occurrence  in  streets  or  interiors. 


THE  GLOBE  LENS  AND  THE  PANTOSCOPE.  77 


Fig.  50. 


Harrison  &  Schnitzer,  in  New  York,  constructed  a  lens  which  is 
distinguished  from  former  lenses  by 
a  very  large  field  of  view.  The  lens 
is  a  double  objective,  A  B  (Fig.  50), 
with  symmetrical,  strongly  curved 
crown  and  flint  glass  lenses,  the 
outer  curves  of  which  form  a 
sphere ;  the  lens  is  provided  with 
stops,  D. 

The  stops  are  a  necessary  part 
of  the  objective.  While  the  pre- 
viously described  lenses,  Portrait 
lens,  Triplet,  and  Aplanatic,  will  give  sharp  pictures  without  any 
stop,  the  Globe  lens  will  show  so  much  spherical  aberration  as  to  make 
the  picture  useless. 

The  consequence  is  that  it  is  inferior  in  light  to  the  previously  de- 
scribed lenses,  but  excellent  in  other  respects. 

The  small  stop  excludes  a  large  quantity  of  light  which  strikes  the 
open  front  lens,  and  only  a  small  portion  which  falls  nearly  vertical 
on  the  lens  is  able  to  exercise  any  effect.  % 

The  annexed  figure  will  illustrate  the  course  of  such  a  bundle  of 
rays.    The  oblique  bundles, 

L  I,  and  N  J,  after  being  re-  fig.  si. 

fracted  by  the  front  lens,  pass 
through  the  centre  of  the  ob- 
jective and  strike  the  points 
B  and  E;  being  here  again 
refracted,  they  leave  the  lens 
parallel  to  their  line  of  inci- 
dence. 

The  original  Globe  lens  of 
Harrison  showed  only  an  an- 
gle of  75°. 

The  Ross  Doublet  shows  equal  capabilities  ;  its  construction,  how- 
ever, is  different  from  that  of  the  Globe  lens. 

Busch,  in  Rathenow,  has  constructed  an  instrument  similar  to  the 
Globe  lens,  which  surpasses  the  latter  lens  in  the  size  of  the  picture, 
and  the  picture  shows  the  astonishing  angle  of  90°  (field  of  view 
105°).  The  picture  which  such  a  lens  furnishes  is  twice  as  long  as 
the  focus  of  the  lens. 

The  arrangement  of  the  lens  is  similar  to  the  Globe,  but  the  exter- 
nal surfaces  are  not  in  the  same  sphere. 


78 


THE  PRACTICE  OF  PHOTOGRAPHY. 


In  a  still  more  perfect  manner  Mr.  Zentmayer  has  accomplished 
the  same  object  by  a  combination  of  two  strongly  convex  simple 
crown-glass  lenses  (Fig.  52).  This  Zentmayer 
lens  is,  particularly  in  America,  where  it  origi- 
nated, very  generally  employed  where  a  short 
distance  and  large  field  of  view  are  required. 

The  back  lens  is  smaller  than  the  front  lens ; 
the  front  lens  can  be  used  again  as  back  lens  of 
the  next  larger  combination,  an  advantage  which 
landscape  photographers  will  fully  appreciate. 

Any  variety  of  combinations  and  series  of 
focal  lengths  might  be  constructed  on  the  above 
principle ;  but  the  plan  adopted  is  as  follows :  • 
The  most  complete  set  consists  of  six  lenses,  the  focal  lengths  of  which 
are — 

I,  .       .       .    5.333  inches.        IV,  18  inches. 

II,  ...    8  "  V,     ...    27  " 

III,  .       .       .12  "  VI,     .  40.5  " 

These  may  all  be  successively  arranged  in  the  same  mounting,  giving 
combinations  with  focal  lengths  and  circular  fields  at  90°  as  follows : 

Lenses  I  and  II  give  a  focal  length  of  3.55  inches,  and  field  7  inches 
diameter. 

Lenses  II  and  III  give  a  focal  length  of  5.33  inches,  and  field  10^ 
inches  diameter. 

Lenses  III  and  IV  give  a  focal  length  of  8  inches,  and  field  16  inches 
diameter. 

Lenses  IV  and  V  give  a  focal  length  of  12  inches,  and  field  24  inches 
diameter. 

Lenses  V  and  VI  give  a  focal  length  of  18  inches,  and  field  36  inches 
diameter. 

Thus,  with  six  lenses  and  one  mounting,  five  different  instruments 
may  be  successively  adjusted  in  as  many  minutes,  the  mounting  being 
so  arranged  as  to  fit  in  the  camera  either  way.  To  pass  from  one 
focal  length  to  the  next  longer  in  the  series,  it  is  only  necessary  to 
take  out  the  smaller  lens  and  put  in  its  place  the  second  size  above. 
Thus,  to  change  8  inches  into  12,  lens  No.  Ill  is  replaced  by  No.  V, 
and  the  mounting  reversed.  A  little  shutter,  close  to  the  central 
diaphragm,  serves  for  "  exposing  "  in  place  of  a  cap  ;  and  a  diaphragm 
plate  is  arranged  with  three  holes  for  each  combination,  a  large 
one  for  focussing,  a  middle  one  for  quick  work,  and  a  small  one  to 


ON  TESTING  OBJECTIVES. 


79 


secure  extraordinary  sharpness ;  for  it  is  one  of  the  merits  of  this  lens 
that  a  large  stop  may  be  used  for  focussing,  and  a  small  one  thrown 
in  for  the  exposure,  with  not  only  good,  but  the  very  best  effect. 

The  decrease  in  the  intensity  of  light  towards  the  margin  is  a  great 
disadvantage  of  the  objectives  with  a  very  large  field  of  view ;  the 
margins  are  frequently  underexposed  when  the  centre  has  received 
its  full  exposure ;  this  becomes  particularly  apparent  when  the  centre 
of  the  field  contains  bright  objects,  while  the  margins  are  occupied  by 
darker  ones. 

In  employing  these  instruments  we  have  to  observe,  also,  that  the 
perspective  is  frequently  exaggerated  ;  the  nearer  objects  appear  too 
large,  while  those  at  a  distance  are  too  small. 

As  another  in  this  line  we  must  mention  Dallmeyer's  Rectilinear 
lens  (Fig.  53).  This  lens  consists  of  two  achromatic  meniscus  lenses, 
A  and  B,  with  a  stop  between  them.  The  position  of  the  stop  has  been 
selected  in  such  a  manner  that  the  bright  spot  in  the  centre  (ghost)  is 
avoided. 

Fig.  53. 

Ar-,. 


The  Rapid  Rectilinear  lens,  lately  constructed  by  Dallmeyer,  re- 
sembles the  older  Steinheil  lens  so  much  that  it  may  be  considered  a 
copy  of  the  latter,  in  which  Dallmeyer  has  only  made  a  few  changes. 

The  latest  invention  of  wide-angled  lenses  is  Steinheil's  Aplanatic 
lens,  which  surpasses  all  others  in  intensity  of  light,  although  it  is,  in 
this  respect,  inferior  to  the  old  Aplanatic  lens.  With  full  opening  it 
yields  a  picture  which  is  sharp  up  to  80°. 

ON  TESTING  OBJECTIVES. 

The  general  method  amongst  photographers  is  to  take  with  a  new 
objective  a  few  trial  plates.  Such  trials  are  very  valuable ;  still  the 
result  is  always  one-sided,  as  it  gives  information  only  in  regard  to 
the  size  of  the  picture,  the  sharpness  towards  the  margin,  and  the  dif- 
ference between  visual  and  chemical  focus,  also  in  regard  to  distortion. 
The  intensity  of  light  is  only  superficially  ascertained,  and  as  for  the 


80 


THE  PRACTICE  OF  PHOTOGRAPHY. 


size  of  the  picture,  this  in  itself  forms  no  criterion  of  the  value  of  an 
objective. 

We  often  hear  the  remark,  that  a  portrait  objective,  which  gives 
a  figure  twice  as  high  as  the  diameter  of  the  lens,  must  be  a  good 
one. 

It  is  only  necessary  to  examine  the  price-list  of  the  opticians  in 
order  to  find  out  that  the  size  of  the  picture,  with  objectives  of  the 
same  opening,  varies  considerably.  So,  for  instance,  the  3-inch  lens 
by  Busch  (page  71)  gives  in 

Focus. 

System  I,  a  picture  of  7    x  9   inches,    12  inches. 
"     II,        "  6    x  7i     «        10T^  " 

"   III,        "  4j  x  6i     "         9T%  " 

"    IV,        "         4J  X  5J    "         7T\  « 

If  we  would  take  the  size  of  pictures  as  the  test,  the  first  should  be 
the  best.  The  last,  however,  which  gives  the  smallest  picture,  is  the 
most  expensive. 

In  what  consists  the  difference  ? 

It  is  in  the  focus.  With  equal  opening,  the  shorter  the  focus  the 
greater  will  be  the  intensity  of  light  of  a  lens.  This  shows  how  impor- 
tant it  is  to  ascertain  the  focal  length  of  an  objective  when  we  wish  to 
judge  of  its  quality.  When  the  focal  length  is  known,  we  can  form  an 
opinion  of  the  intensity  of  light. 

The  intensities  of  light  are,  with  equal  opening,  the  reverse  of  the 
squares  of  the  foci. 

When  we  take,  for  instance,  No.  IV  and  No.  I  for  comparison,  the 
strength  of  light  is  proportioned  as  122  to  7t7q2 — i.  e.,  as  144  to  59T2095, 
or  almost  as  2\  to  1. 

Hence  System  IV  has  2^  times  the  intensity  of  light  of  System  I, 
and  in  this  consists  its  superiority  (see  table,  page  71,  on  the  relation 
of  intensity  of  light  in  the  different  systems,  and  the  time  of  exposure 
necessary  for  each  one).  The  focal  lengths,  however,  are  generally 
only  approximately  stated  in  the  different  price-lists.  Many  persons 
think  that  focal  leugth  is  the  distance  between  the  ground-glass  and 
the  back  lens,  when  the  system  stands  in  focus,  or  what  is  the  same, 
projects  a  sharp  picture  on  the  ground-glass.  This  is  correct  only  for 
the  simple  leus,  but  not  for  a  compound  combination. 

For  a  combination  of  lenses,  the  focus,  and  the  distance  of  the 
ground-glass  from  the  back  lens,  are  two  entirely  different  things. 

For  an  example,  I  will  select  the  Steinheil  lens.  Its  focus,  accord- 
ing to  the  price-list,  is  10J  Parisian  inches,  or  0.276  metre.  Accord- 


ON  TESTING  OBJECTIVES. 


81 


ing  to  my  measurements  it  was  0.296  metre.  Similar  discrepancies 
happen  frequently,  and  as  it  happens  very  often  that  one  does  not 
know,  by  the  focus,  whether  the  distance  of  the  back  lens  from  the 
ground  glass,  or  the  actual  equivalent  focus,  is  meant,  the  importance 
to  determine  the  length  of  focus  becomes  evident.  Different  methods 
have  been  recommended.  I  have  tried  them  all,  and  consider  the 
following  the  simplest  and  most  reliable. 

The  objective  which  is  to  be  tested,  is  placed  on  a  long  camera ;  a 
strip  of  black  paper,  of  about  four  inches  in  length,  with  parallel 
sides,  is  cut  out,  and  afterwards  divided  again  lengthways.  The  one 
piece  is  pasted  on  a  board,  or  on  a  piece  of  Bristol  board ;  the  other 
piece  is  pasted  on  the  ground-glass ;  both  are  pasted  in  a  vertical 
direction.  The  objective  is  now  focussed  on  the  black  strip,  and  the 
camera  is  moved  backward  and  forward  until  the  image  on  the 
ground-glass  corresponds  exactly  in  size  with  the  piece  pasted  on  to  it. 
To  make  the  upper  line  of  the  image  exactly  correspond  with  the 
same  line  on  the  ground-glass,  it  will  only  be  necessary  to  fasten  with 
a  string  the  board  carrying  the  black  paper  to  a  nail  in  the  wall,  and 
to  raise  and  lower  it  until  the  lines  coincide ;  when  the  lower  lines 
likewise  coincide,  the  instrument  is  removed  from  the  camera  with- 
out changing  the  position  of  the  latter,  and  the  distance  between 
object  and  ground-glass  is  exactly  ascertained  ;  by  dividing  this  dis- 
tance by  four  we  get  at  the  equivalent  focus  of  the  lens. 

It  is  advisable  to  paste  a  piece  of  paper  with  small  print  on  it  upon 
the  black  strip,  as  it  facilitates  focussing. 

When  we  know  the  focal  length,  we  can  draw  a  very  nearly  cor- 
rect conclusion  in  regard  to  the  intensity  of  light. 

The  opening  is  divided  by  the  focal  length,  and  the  square  of  this 
figure  is  found.    So  is,  for  instance,  the  fraction  for — 


Voigtlander  C.  de  Visite.      Auzoux  3  inch.      Busch's  Portrait  Triplet.  Steinheil. 

68.5                   76  64^  43.5 

230.4                350.5  390  303.06 

Or  expressed  in  simple  figures — ■ 

JL           JL  1  JL 

3T\                   4f  6  7 

The  squares  of  these  figures  are — 

1                      1  1  1 

11.3                  21  36  49 


Theoretically,  the  intensity  of  light  of  the  different  objectives  will 
bear  the  same  relation.    Practically,  there  are  many  exceptions  to 

6 


82 


THE  PRACTICE  OF  PHOTOGRAPHY. 


this  rule;  the  more  or  less  fine  polish,  the  color  and  form  of  the  glass, 
play  an  important  part,  but  the  above  calculation  will  give  an  ap- 
proximation. 

As  important  as  the  determination  of  the  focal  length  is  for  finding 
the  intensity  of  light,  so  also  it  serves  to  determine  the  extent  of  the 
field  of  view.  The  lens  is  screwed  to  a  very  large  camera  in  order  that 
the  circle  of  light  may  be  completely  visible  on  the  ground-glass. 

The  diameter  of  the  circle  should  be  exactly  measured,  and  trans- 
ferred to  a  piece  of  paper  (see  a,  b,  Fig.  42).  In  the  centre  a  vertical 
line  should  be  erected,  d,  c,  its  length  being  the  same  as  the  focal 
length  of  the  lens,  and  we  next  construct  the  triangle,  a,  d,  b.  The 
angle  at  d  is  the  field,  of  view  of  the  lens.  This  angle  is  easily  measured 
with  a  protractor. 

The  possessors  of  trigonometrical  tables  do  not  require  this  con- 
struction, but  can  determine  the  angle  from  the  radius  of  the  circle 
of  light  and  the  focus.  The  tangent  of  half  the  angle  of  the  field  of 
view  is  equal  to  the  radius  of  the  circle  of  light  divided  by  the  focus. 

When  we  take  a  picture  in  which  the  whole  circle  of  light  is  visi- 
ble, we  will  find  that  only  the  central  part  is  sharp  and  fit  for  use  ; 
but  by  substituting  smaller  stops  the  sharpness  will  extend  further 
and  further  towards  the  margins.  How  far  the  sharpness  is  useful 
for  practical  purposes  depends  entirely  on  individual  opinion.  Some 
photographers  are  in  this  respect  extremely  pedantic,  while  others 
are  satisfied  with  moderate  results. 

The  nature  of  the  object  also  (whether  portrait,  landscape,  or  re- 
productions) plays  an  important  part.  When  we  desire  to  determine 
how  large  the  actual  practically  useful  field  of  a  lens  is,  we  have  to 
find  out  the  extreme  points  where  the  sharpness  is  still  sufficient,  and 
then  apply  a  rule  and  ascertain  the  diameter  of  the  practically  useful 
surface. 

When  we  execute  the  same  construction  as  above,  we  will  find  the 
practical  angle  of  the  field  of  the  picture. 

The  introduction  of  stops  has  of  course  a  considerable  influence  in 
extending  the  field ;  and  in  comparing  the  performance  of  two  objec- 
tives, the  sizes  of  the  stops  must  not  be  overlooked.  It  is,  however, 
incorrect  to  measure  the  size  of  the  stop  only.  In  order  to  get  a  cor- 
rect guide,  the  size  of  the  stop  should  be  divided  by  the  focal  length 
of  the  respective  objectives. 

The  size  of  the  picture  is  only  to  be  considered  when  the  instrument 
is  nearly  in  focus  with  the  ground-glass.  It  is  quite  different  when 
the  picture  is  removed  from  the  focus.  A  carte  de  visite  lens,  for  in- 
stance, will  give  in  its  focus  a  picture  of  about  three  inches ;  but  an 


THE  STEREOSCOPE. 


83 


object  three  inches  long,  placed  in  the  focus  of  the  lens,  would  if  pro- 
jected  on  a  screen,  or  on  the  ground-glass,  be  five  feet  long.  The  size 
of  the  picture  is,  hence,  only  relative,  when  expressed  in  definite 
terms,  while  the  angle  of  the  picture  remains,  under  all  circumstances, 
the  same. 

To  test  for  focal  differences,  a  large  book  or  a  newspaper  which  has 
been  pasted  upon  a  piece  of  pasteboard  should  be  placed  obliquely  in 
front  of  the  lens,  the  lens  should  be  focussed  sharply  upon  the  middle 
line,  and  the  camera  should  be  placed  at  such  a  distance  that  the  let- 
ters are  about  the  natural  size. 

We  now  take  a  picture;  if  the  line  upon  which  we  have  focussed  is 
sharp,  then  the  lens  has  no  focal  difference ;  if  another  line  is  sharp 
the  lens  has  either  focal  difference,  or  the  position  of  the  plate  in  the 
plate-holder  and  the  ground-glass  in  the  focussing  glass  do  not  coin- 
cide exactly.  To  find  out  if  the  plate-holder  is  at  fault,  we  discard 
the  ground-glass  frame  and  focus  with  the  plate-holder  by  placing  in 
it  a  piece  of  ground-glass  of  suitable  size.  If  again  another  line  than 
the  one  on  which  we  have  focussed  appears  sharp,  we  may  be  sure  that 
the  lens  has  a  focal  difference. 

To  take  with  such  a  lens  a  sharp  picture  requires  a  correction  in 
the  mode  of  focussing.  Suppose  that  instead  of  the  first  line  upon 
which  we  have  focussed  the  third  line  should  come  out  sharp,  then  it 
follows  that  in  order  to  obtain  a  sharp  picture  of  the  third  line  we 
must  focus  upon  line  one. 

If  we  mark  on  the  objective  the  place  when  the  lens  is  focussed 
for  line  one,  and  also  when  focussed  upon  line  three,  and  the  lens  has 
to  be  moved  forward  for  the  space  of  this  difference  after  having 
sharply  focussed  for  an  object  in  order  to  obtain  a  sharp  picture,  it 
must  be  remembered  that  this  difference  varies  with  the  distance  of 
the  camera  from  the  objective. 

If,  for  instance,  we  wish  to  fix  the  focus  difference  for  portraits,  the 
test  object  should  be  placed  at  the  distance  where  the  sitter  is  to  be 
placed. 

THE  STEREOSCOPE. 

When  we  look  with  both  eyes  at  a  near  object,  the  view  which  each 
eye  obtains  of  the  object  will  be  different.  The  left  eye  will  see  more 
of  the  left  side,  and  the  right  eye  will  see  more  of  the  right  side  of  a 
body.  Both  views  combined  produce  the  effect  of  solidity.  In  1838, 
Wheatstone  tried  to  produce  a  similar  effect  by  looking  at  two  pic- 
tures, one  of  which  represented  the  object  as  it  would  appear  to  the 
left  eye,  the  other  gave  the  right-eyed  view ;  and  his  experiment  was 


84  THE  PRACTICE  OF  PHOTOGRAPHY. 

successful.  He  saw  the  plain  figures  solid.  The  figures  employed  by 
him  were  drawn  by  hand,  and  consisted  of  lines  and  circles.  The 
construction  of  pictures  representing  complicated  objects,  as  land- 
scapes and  persons,  offered  greater  difficulties ;  and  such  pictures  be- 
came only  possible  by  means  of  photography.  At  the  same  time  a 
handy  instrument  for  viewing  these  pictures  was  invented  by  Brewster, 
which  he  called  the  stereoscope,  an  instrument  which,  at  the  present 
day,  is  found  in  every  drawing-room.  Stereoscopic  pictures  and 
cartes  de  visite  rival  each  other,  and  both  of  these  articles  have  be- 
come an  incentive  for  the  photographer  to  furnish  the  most  perfect 
productions  for  the  lowest  price. 

Brewster's  stereoscope  consists  of  two  prismatic  pieces  of  glass,  L  U 
(Fig.  54),  which,  when  attached  to  each  other  by  their  bases,  would 
form  a  biconvex  lens.    Both  the  prismatic  glasses 
FlG-  54,  are  mounted  in  a  piece  of  wood  in  such  a  manner 

\  /  that  the  points  are  opposite  to  each  other,  and  that 

\         /  both  correspond  to  the  position  of  the  eyes.  When 

\       I  we  now  look  at  a  stereoscopic  picture,  through 

LCI^f^yZl  JL'  these  glasses,  by  bringing  them  close  to  the  eye, 
and  placing  the  picture  at  a  distance  where  the 
\\    \  objects  appear  plainest,  the  two  pictures  will  ap- 

I  1  pear  as  one,  and  give  a  perfectly  plastic  impres- 

(L   a"  it'  sion. 

The  coalescence  is  explained  by  the  fact  that 
the  lenses  act  like  prisms — i.  e.,  divert  the  lenses  of  the  eye  in  the 
direction  of  the  refracting  edges. 

Suppose  that  a  and  a'  are  two  corresponding  points  in  the^  stereo- 
scopic picture,  and  L  and  U  the  lenses,  then  the  rays  a  b  and  a  V 
will  be  so  diverted  that  they  will  appear  as  if  they  proceeded  from  a 
single  point,  a". 

In  order  that  this  appearance  may  take  place  in  a  normal  manner, 
it  is  necessary  that  the  pictures  should  be  mounted  at  a  proper  dis- 
tance from  each  other.  A  trial  will  soon  establish  the  necessary  dis- 
tance. As  the  stereoscopic  glasses  are  lenses,  they  act  at  the  same 
time  as  magnifiers ;  they  enlarge  the  picture.  Lenses  have  the  effect 
of  placing  the  objects  at  the  distance  of  most  distinct  vision,  and  as 
this  distance  is  different  in  different  individuals,  it  follows  that  the 
distance  of  the  glasses  from  the  picture  depends  on  the  individuality 
of  the  observer. 

For  this  purpose  stereoscopes  have  been  made  where  the  glasses  can 
be  moved,  or  where  the  picture  can  be  brought  nearer  to  or  removed 
further  from  the  glasses.    The  latter  is  the  case  with  the  American 


THE   PANORAMIC  APPARATUS. 


85 


Stereoscope  (Fig.  55).  This  is  an  open  instrument,  in  which  the  pic- 
ture receives  light  from  every  direction,  and  is  consequently  much 
better  lighted  than  is  the  old  box  stereoscope. 


Generally  the  picture  is  near  the  focus  of  the  lens  with  which  we 
view  it ;  it  is  essential  also  that  the  focal  length  of  the  lenses  with 
which  we  view  a  stereoscopic  picture,  should  be  of  nearly  the  same 
length  as  those  with  which,  the  picture  was  taken.  When  this  is  not 
the  case  a  wrong  stereoscopic  effect  will  be  produced,  and  this  causes 
the  exaggerated  perspective  in  pictures  which  have  been  taken  with 
lenses  of  very  short  focus,  and  are  viewed  with  lenses  of  only  slight 
magnifying  power. 

Stereoscopic  pictures  are  either  taken  with  a  camera  with  two  ob- 
jectives, the  distance  between  them  being  about  the  same  as  the  dis- 
tance between  the  eyes  (2J  inches),  or  they  are  taken  with  a  single 
objective  by  placing  the  camera  first  in  the  position  of  the  right  eye, 
and  then  the  left. 

For  very  distant  objects,  the  distance  has  to  be  increased  in  order 
to  recover  the  plastic  effect ;  in  landscapes  this  amounts  sometimes  to 
as  much  as  several  feet.  For  near  objects  excessive  distance  exagger- 
ates the  prominent  points,  and  in  case  of  a  person,  the  nose  or  hands 
seem  to  project  several  feet  from  the  body. 


The  generality  of  photographic  apparatus  has  only  a  very  limited 
field  of  view,  and  does  not  admit  of  taking  a  view  of  considerable 
lateral  extension,  such  as  we  frequently  meet  with  at  the  seashore  or 
in  the  mountains;  for  instance,  the  panorama  of  the  Rigi,  or  the 
Faulhorn.    Martens,  an  engraver  in  Paris,  conceived  the  idea  of 


Fig.  55 


THE  PANORAMIC  APPARATUS. 


86 


THE  PRACTICE  OP  PHOTOGRAPHY. 


Fig.  56. 


taking  such  pictures  with  a  rotating  camera,  which  would  successively 
take  in  the  whole  horizon. 

He  constructed,  in  1847,  a  camera  with  a  cylindrical  daguerreo- 
type plate ;  the  plate  remained  stationary  while  the  camera  with  the 
objective  revolved ;  the  light  acted  on  the  plate  through  a  small  slit. 
It  is  easily  demonstrated  that,  in  spite  of  the  revolving  motion  of  the 
ca  nera,  the  picture  of  the  same  object  must  always  be  projected  on 
tho  plate  in  the  same  spot.  The  image  of  a  point  lies  always  on  the 
straight  line  which  is  drawn  from  the  point  through  the  centre  of  the 
lens. 

When  a  (Fig.  56)  is  such  a  point,  and  o  the  centre  of  the  objective, 
P,  P,  the  cylindrical  plate,  then  the  image  of  the  point  will  be  on  a 
line,  a  b,  drawn  through  the  plate  from  o.  When  now  the  objective  is 

moved  around  its  centre  (as  is  indicated 
in  the  figure  by  the  dotted  lines),  then 
the  image  of  a,  according  to  the  principle 
stated  above,  will  still  remain  on  the 
same  line,  a  b  (because  a  and  o  do  not 
change  their  positions),  and  will  fall 
again  on  the  point  b  of  the  plate,  and 
notwithstanding  that  the  objective 
moves  constantly,  all  the  points  of  the 
object  will  be  sharply  defined  in  the 
picture. 

The  above  holds  good  only,  of  course, 
when  the  rays  do  not  form  too  large  an 
angle  with  the  axis.  To  prevent  this,  a 
diaphragm  with  a  narrow  slit  is  placed 
opposite  the  lens,  the  opening  of  which 
is  parallel  to  the  axis  of  rotation,  and 
which  moves  simultaneously  with  the  objective. 

The  fault  of  Martens's  apparatus  is  the  cylindrical  plate,  the  prep- 
aration of  which  in  the  ordinary  collodion  process  offers  great  diffi- 
culties. 

Brandon  introduced  in  its  place  a  plane  plate,  which,  during  the 
rotation,  rolls  itself,  so  to  speak,  off  the  cylindrical  surface  of  the 
image,  following  the  motions  of  the  objective. 

The  mechanism,  to  execute  the  motion  in  an  exact  manner,  differs 
widely,  and  the  opinions  vary  considerably  as  to  which  manner  of 
construction  is  the  most  practical. 

Generally  the  camera,  G,  Fig.  57,  with  the  objective,  o,  is  placed 
on  a  horizontal  metallic  plate,  S,  S;  the  camera  rests  on  small  wheels 


THE  PANORAMIC  APPARATUS. 


87 


and  revolves  around  an  axis  which  passes  through  the  optical  centre 
of  the  objective. 

The  wheels  are  moved  by  clock-work.  The  plate-holder  runs  in  a 
movable  groove,  as  in  a  carte  de  visite  camera.  A  cord  wound 
around  the  disk,  S,  S,  the  ends  of  which  run  off  in  the  direction  of 
the  tangent,  and  which  are  fastened  to  the  ends  of  the  plate-holder 
at  a,  causes  the  latter  to  move,  and  to  occupy  successively  the  posi- 
tions which,  in  the  annexed  figure,  are  illustrated  in  three  phases, — 
beginning  at  K ,  K\  centre  at  K,  K,  end  of  motion  at  K",  K". 

The  pictures  obtained  with  this  apparatus  are  evidently  projections 
on  a  cylinder  unrolling  itself.  The  vertical  lines  are  reproduced  ver- 
tical, but  the  horizontal  ones,  unless  they  coincide  with  the  horizon  of 
the  apparatus,  are  represented  as  curves. 


Fig.  57. 


When  we  take  a  house  front  or  a  street  with  this  apparatus,  the 
top  lines  will  appear  as  an  upward  curved  line,  while  the  base  lines 
will  be  curved  in  the  opposite  direction,  which  effect  becomes  more 
unpleasant  when  the  line  is  very  long  and  far  removed  from  the 
horizon. 

For  architectural  views  this  apparatus  can  only  be  used  to  a  very 
limited  extent,  and  a  wide-angled  lens  is  decidedly  preferable. 


88 


THE  PRACTICE  OP  PHOTOGRAPHY. 


CHAPTER  IV. 

THE  NEGATIVE  PROCESS. 

SECTION  I. 
PREPARATION  OF  THE  CHEMICALS. 

Rules  of  Precaution. 

A  piece  of  paper  and  a  lead-pencil  are  sufficient  for  a  draughtsman 
to  reproduce  or  to  make  the  picture  of  any  object.  He  spreads  the 
paper,  he  points  his  pencil,  and  all  his  preparations  are  made.  The 
work  can  commence. 

It  is  quite  different  in  photography.  Even  to  make  the  smallest 
and  least  important  picture  requires  a  quantity  of  apparatus — camera, 
tripod,  lenses,  plate-holder,  dishes,  bottles,  basins,  and  a  number  of 
solutions — silver-bath,  developer,  fixing-bath,  &c,  and  the  prepara- 
tions, which,  for  the  draughtsman,  are  made  in  a  few  seconds,  may, 
for  the  photographer,  require  hours.  He  has,  however,  the  other  ad- 
vantage, that  the  taking  of  the  picture  will  be  accomplished  in  a  few 
minutes,  while  a  draughtsman  would  have  to  work  hours  or  days,  and 
then  he  would  have  but  one  picture,  while  the  photographer  will  have 
a  plate  from  which  he  can  produce  hundreds  or  even  thousands  of 
prints. 

The  preparation  is  therefore  the  main  thing  in  photography,  and  it 
must  be  made  with  the  greatest  accuracy  and  cleanliness  on  the  one 
side,  and  with  presence  of  mind,  knowledge,  and  taste  on  the  other,  if 
we  expect  to  realize  a  satisfactory  result. 

What  advantage  is  there  in  the  best  collodion,  and  the  cleanest 
and  most  carefully  prepared  plate,  if  the  person  represented  is  ill 
posed  or  badly  illuminated ;  what  advantage,  on  the  other  hand,  is 
the  most  tasty  arrangement  when  the  silver-bath  refuses  to  work 
properly?  And  what  shall  I  do  with  a  plate  prepared  with  the  best 
material,  clean  and  perfect  in  every  particular,  and  the  object  repre- 
sented be  ever  so  beautiful,  if  the  lens  does  not  work  properly,  or  the 


RULES  OF  PRECAUTION. 


89 


focussing  has  been  carelessly  performed,  and  the  "picture  looks  dis- 
torted and  does  not  possess  sufficient  sharpness? 

Each  separate  branch  of  the  preparatory  work,  and  there  are  many 
of  them,  must  be  carried  out  with  the  greatest  care.  Nothing  must 
be  forgotten,  and  nothing  must  be  considered  as  being  of  little  moment. 
And  whoever  does  not  go  to  work,  in  this  respect,  with  the  greatest 
and  most  conscientious  care,  will  never  become  a  great  photographer, 
but  always  remain  an  incompetent. 

I  would  advise  beginners  in  particular  not  to  attempt  to  take  a 
picture  until  they  feel  fully  convinced  that  all  the  apparatus  and 
chemicals,  from  first  to  last,  are  in  a  normal  state  and  ready  for  use. 
How  often  has  it  happened  to  me,  with  my  scholars,  that  a  plate  has 
been  coated  with  collodion  and  has  become  dry  because  the  dipper 
was  not  handy.  How  often  has  an  exposed  plate  been  spoiled  be- 
cause the  developer  was  not  handy  or  had  not  been  made  at  all,  not 
to  mention  numberless  other  "  accidents." 

The  preparations  are,  according  to  the  nature  of  the  work,  very 
different.  They  are  different  for  the  negative  and  different  for  the 
positive  process,  different  for  the  carbon  print,  and  different  for  the 
silver  print,  or  the  enamel  process.  "We  will  first  consider  the  pro- 
cess on  which  all  the  others  depend, — i.  e.,  the  negative  process. 

The  chemicals  necessary  for  the  different  photographic  processes 
are  generally  mixed  beforehand  ready  for  use.  The  especially  im- 
portant mixtures  are  the  collodion,  the  silver  bath,  the  developer,  the 
intensifier,  and  the  fixing  solution.  These  fluids  are  absolutely  neces- 
sary before  one  can  commence  to  work,  and  they  must  be  in  such  a 
condition  that  we  can  rely  on  their  good  qualities.  In  their  prepara- 
tion, preservation,  and  treatment  the  greatest  care  is  necessary,  and 
particularly  the  greatest  cleanliness  is  to  be  observed  in  the  prepara- 
tion of  the  collodion  and  nitrate  bath.  When  a  mistake  has  been 
made  it  will  manifest  itself  in  every  plate,  and  success  becomes  im- 
possible. The  utmost  care  is  therefore  the  more  necessary,  as  even 
the  smallest  homoeopathic  quantities,  which  can  hardly  be  traced  by 
analytical  tests,  when  present  in  the  collodion  or  in  the  bath,  are  apt 
to  make  all  photographic  success  an  illusion. 

The  author  knows  hundreds  of  photographers,  who,  either  from 
carelessness  or  ignorance,  neglected  to  clean  a  funnel,  and,  without 
suspecting  it,  ruined  their  collodion  or  nitrate  bath,  and  who  after- 
wards had  ten  times  as  much  trouble  to  restore  their  chemicals  to 
working  order,  as  it  would  have  taken  to  give  to  the  funnel  the  most 
thorough  cleaning. 


90 


THE  PRACTICE  OF  PHOTOGRAPHY. 


1.  PREPARATION  OF  THE  COLLODION. 

The  great  care  which  has  been  recommended  above  refers  particu- 
larly to  the  preparation  of  the  collodion.  A  silver  bath  is  easily 
mixed,  and  it  can  be  used  at  once  if  the  old  bath  should  refuse  to 
work.  A  new  collodion,  however,  can,  under  most  favorable  circum- 
stances, only  be  used  successfully  a  day  after  it  has  been  mixed. 

The  photographic  collodion  is  a  solution  of  pyroxylin  in  a  mixture 
of  alcohol  and  ether,  with  which  certain  salts  are  mixed,  the  so-called 
iodizing  salts ;  it  serves  to  produce  the  sensitive  film. 

When  a  glass  plate  is  coated' with  this  collodion,  a  film  containing 
a  combination  of  collodion  and  this  iodizing  salt  will  remain  on  the 
glass ;  when  this  plate  is  now  dipped  into  the  nitrate  bath,  the  salts 
of  iodine  and  bromine  will  decompose,  and  iodide  and  bromide  of 
silver  (which  are  very  sensitive  to  light)  will  take  their  place  on  the 
film,  while  a  combination  of  nitric  acid  with  a  base  will  remain  in  the 
bath. 

We  will  first  consider  the  properties  of  pyroxylin  (gun-cotton). 
How  it  is  made  I  will  not  explain  here,  for  I  hardly  think  that  a 
photographer  will  attempt  to  make  it  himself,  as  there  are  plenty  of 
sources  from  which  to  get  a  good  and  reliable  article. 

PYROXYLIN. 

The  pyroxylin  is  obtained  from  cellulose  or  vegetable  fibre,  which 
forms  the  main  substance  of  wood,  paper,  cotton,  and  all  vegetation. 
It  was  discovered  in  1846  by  Schonbein,  and  attracted  at  that  time, 
under  the  name  of  gun-cotton,  great  attention  as  a  substitute  for  gun- 
powder. 

Pyroxylin  is  a  substance  which  is  obtained  by  placing  cotton  or 
linen  paper  into  a  mixture  of  concentrated  nitric  and  sulphuric  acids, 
and  afterwards  by  careful  washing  in  water,  and  drying.  A  peculiar 
process,  the  process  of  substitution  takes  place,  and  C12  H10  O10  (or 
cellulose)  loses  three  or  less  atoms  of  hydrogen  (H),  which  are  replaced 
by  nitrous  acid  (N04).  The  so  changed  cotton  has  not  altered  its 
form.  To  the  touch,  it  is  a  little  more  coarse,  but  its  chemical  properties 
are  materially  different.  Its  weight  has  been  increased  by  a  quarter 
to  one-half.  It  explodes  by  being  lighted ;  it  is  soluble  in  acetic  ether, 
also  in  alcohol-ether,  and  on  evaporation  of  the  solvent,  it  separates 
as  a  vitreous  film.  On  this  property  the  employment  of  pyroxylin  as 
the  picture-carrier  depends.    Potassium  dissolves  it  by  decomposing 


PYROXYLIN. 


91 


it  and  N05  and  N03.  Salts  are  formed,  and  also  an  organic  com- 
pound which  reduces  the  salts  of  silver,  and  is  used  for  silvering. 

When  pyroxylin  is  treated  with  reducing  agents,  for  instance,  acetic 
acid  and  iron,  it  is  changed  to  ordinary  cotton.  Of  all  the  properties 
of  pyroxylin,  the  photographic  one  interests  us  here  the  most,  i.  e.,  the 
solubility  in  alcohol-ether,  and  the  quality  to  yield,  on  evaporation,  a 
perfectly  homogeneous,  vitreous,  and  transparent  film,  which  possesses 
sufficient  firmness  to  withstand  the  action  of  a  spray  of  water,  and  which 
is  as  indifferent  as  possible  to  the  various  photographic  chemicals. 

Formerly  only  one  kind  of  pyroxylin  or  nitro-cellulose  was  recog- 
nized, but  it  soon  was  found  that  the  solubility  in  alcohol-ether  was 
variable ;  that  some  pyroxylin  is  not  soluble,  and  that  on  the  other 
hand  the  solutions  of  the  same  showed  different  qualities  according  to 
the  mode  of  preparation,  and  fulfilled  the  above-mentioned  conditions 
of  their  photographic  usefulness  perfectly.  This  gave  rise  to  a  close 
study  of  these  modifications.  Hadow  made  a  very  careful  investiga- 
tion, and,  based  on  these  experiments,  he  describes  the  following  four 
kinds  of  pyroxylin : 


1. 

^36 

n2r 

*9 . 

^o30 

=  c12  ^  o10 

2. 

^36 

X8  J 

^°30 

3. 

C36 

H23  ' 

^o30 

4. 

^36 

x6  J 

>o30 

Hadow  triplicates  the  formula  of  cellulose — X  is  a  simple  sign  for 
N04. 

The  combinations  are  obtained  by  immersion  in  acid  mixtures  of 
different  intensities. 

No.  1,  by  immersion  in  the  strongest,  the  other  No.  in  weaker  ones. 
In  regard  to  their  explosiveness  and  solubility,  they  show  very  great 
differences. 

No.  1  is  the  explosive  gun-cotton.  This  is  insoluble  in  alcohol  and 
ether,  but  soluble  in  acetic  ether.  It  separates  on  evaporation  as  a 
white  powder.  It  is  useless  for  photographic  purposes,  but  excellent 
for  blasting. 

Nos.  2  and  3  are  soluble  in  alcohol-ether,  even  in  absolute  alcohol, 
and  No.  3  in  glacial  acetic  acid.  On  evaporating  an  alcohol-ether 
solution  a  glassy-looking  film  remains  well  adapted  to  photographic 
purposes. 


92 


THE   PRACTICE   OF  PHOTOGRAPHY. 


No.  4  is  soluble  in  the  same  solvents,  but  leaves  on  evaporation  an 
opaque  film,  and  is  useless  for  photographic  purposes. 

It  follows  from  the  above  that  only  Nos.  2  and  3  can  be  used  for 
photographic  purposes.  They  are  obtained  by  immersion  in  nitric  acid 
of  a  certain  strength.  If  the  acids  are  stronger  we  obtain  No.  1,  or  ex- 
plosive gun-cotton  ;  if  weaker,  the  result  will  be  No.  4. 

The  commercial  pyroxylins  are  but  seldom  simple  compounds,  but 
generally  mixtures  of  the  above-described  varieties. 

But  as  ordinary  cellulose,  although  unchanged  in  composition,  shows 
great  physical  differences  (compare,  for  instance,  cotton,  linen,  velvet, 
wood  or  paper),  so  also  are  the  physical  properties  of  the  pyroxylin 
and  the  collodion  prepared  from  it  very  variable. 

Pyroxylin  is  generally  made  from  cotton  or  silk  tissue-paper;  when 
made  from  the  latter  it  is  called  papyroxylin.  When  carefully  made 
the  one  is  as  good  as  the  other. 

For  the  wet  process  a  cotton  should  be  selected  which  has  been 
made  at  not  too  high  a  temperature.  Such  a  cotton  is  long-fibred, 
yields  a  thick  collodion,  and  contains  but  little  foreign  substance. 
Generally,  however,  gum-like  substances  are  found  in  it  which  cannot 
be  removed  by  washing,  and  which  gradually  will  change  the  nitrate 
bath ;  they  are  called  in  photography  organic  matter.  A  recently  in- 
troduced cotton  which  is  sold  under  the  name  Celloidin,  is  free  from 
these  impurities,  and  therefore  recommends  itself  for  photographic 
purposes. 

Gun-cottons  prepared  at  a  very  high  temperature  have  a  shorter 
staple,  are  dusty,  and  yield  a  thin  solution ;  these  are  better  suited  for 
dry  plates.  It  is  advisable  to.  test  commoner  gun-cotton  for  acidity. 
A  small  sample  is  moistened  with  distilled  water,  and  pressed  upon  a 
piece  of  blue  litmus-paper;  if  the  latter  turn  red,  the  cotton  contains 
acid;  the  acid  is  removed  by  washing  with  distilled  water,  to  which  j\ 
of  ammonia  has  been  added.  The  cotton  is  next  dried;  this  is  done  in 
a  porcelain  or  metallic  dish,  over  boiling  water.  It  has  lately  been 
tried  to  purify  gun-cotton  by  dissolving  it  in  alcohol  and  ether,  and 
pouring  the  solution  in  a  large  quantity  of  water.  The  pure  dissolved 
pyroxylin  precipitates,  is  washed  and  dried;  the  foreign  substances 
remain  in  the  water.  We  prefer  the  celloidin,  which  is  also  pure  and 
cheaper. 

Pyroxylin  is  soluble  in  different  substances,  as,  for  instance,  in  acetic 
ether,  in  acetous  or  nitrobenzole,  &c. 

The  best  photographic  solvent  is  a  mixture  of  alcohol  and  ether, 
from  which  the  collodion  on  evaporation  separates  as  a  transparent 
glutinous  film.    The  properties  of  this  film  vary  not  only  with  the 


PYROXYLIN.  93 


kind  of  pyroxylin  employed,  but  depend  also  on  the  qualities  of  the 
solvents  that  have  been  used.  The  more  rapidly  they  evaporate  the 
more  firm  will  be  the  film,  and  with  sloiv  evaporation  the  film  will  be  cor- 
respondingly soft. 

With  an  excess  of  ether  the  film  becomes  strong  and  cohesive,  con- 
tracts easily,  and  does  not  adhere  firmly  to  the  glass ;  it  can  often  be 
removed  entirely  from  the  plate  without  tearing  it. 

With  an  excess  of  alcohol  the  film  is  tender  and  tears  easily.  This 
is  the  case  to  a  still  greater  extent  when  the  collodion  contains  water. 

When  to  a  good  collodion  water  is  added,  a  precipitate  will  be 
formed,  which  will  redissolve  on  shaking.  The  collodion  is  now 
slimy ;  the  film  seems  transparent,  netted,  and  very  tender.  These 
faults  will  show  themselves  when  we  employ  an  alcohol  containing 
much  water ;  to  obviate  it,  we  have  to  increase  the  proportion  of  alco- 
hol. Here,  however,  another  drawback  manifests  itself  very  soon : 
the  ether  evaporates  and  the  remaining  collodion  yields  as  tender 
films  as  before;  such  a  collodion  can  be  improved  again  by  addiug 
ether  to  it. 

How  much  alcohol  and  ether  are  necessary  depends  on  the  raw  ma- 
terial. For  cotton  which  shows  a  tendency  to  give  a  slimy  and  rotten 
film,  much  ether  and  I  —  j\  alcohol  should  be  taken.  For  cotton 
which  has  been  prepared  at  a  high  temperature,  and  with  a  mixture 
containing  much  sulphuric  acid,  and  which,  in  consequence,  gives  a 
firm,  structureless,  rapidly  drying,  and  easily  contracting  film — i.  e.,  a 
parchment-like  collodion — more  alcohol  than  ether  should  be  used. 

The  strength  of  the  alcohol  is  very  important.  For  slimy  collodion 
the  alcohol  should  be  absolute,  while  for  a  parchment-like  sample  the 
alcohol  may  contain  water.  Hardwich  recommends  for  the  latter, 
when  the. alcohol  is  absolute,  2  parts  alcohol  to  1  ether. 

For  hot  seasons  and  climates  a  collodion  with  much  alcohol  is  to  be 
recommended,  as  it  will  otherwise  dry  too  rapidly.  According  to 
Hardwich,  the  alcohol  not  only  acts  physically,  but  also  photographi- 
cally. It  increases  the  sensitiveness  and  the  intensity.  The  former  is 
only  up  to  a  certain  limit  increased  by  the  addition  of  alcohol :  when 
this  limit  is  exceeded  a  diminution  takes  place ;  but  it  is  different  with 
the  intensity,  which,  particularly  in  warm  weather,  with  a  collodion 
containing  much  ether,  is  very  feeble.  The  porous  character  of  the 
film  certainly  exercises  an  influence  here. 

The  amount  of  cotton  exercises  a  great  influence  on  the  sensitive- 
ness. The  more  cotton  a  collodion  contains  the  greater  will  be  its  sensi- 
tiveness. This  holds  good  at  least  to  a  certain  extent.  Of  different 
samples  of  cotton,  the  one  which  yields  the  thickest  collodion  is  gener- 


94 


THE  PRACTICE  OF  PHOTOGRAPHY. 


ally  the  most  sensitive,  provided  that  the  quantities  of  alcohol  and 
ether  are  equal.  When  a  cotton  turns  out  a  very  limpid  collodion,  it 
is  advisable  to  make  it  a  little  more  concentrated.  Plain  collodion 
should  be  made  first ;  this  should  be  left  to  settle,  and  to  the  clear 
solution  the  iodizing  salts  should  be  added. 

In  Germany  we  generally  take  for  plain  collodion  one-half  alcohol 
and  one-half  ether.  Both  must  be  neutral,  pure,  and  free  from  essen- 
tial oils.  The  cotton  is  weighed  out,  say,  for  instance,  20  grammes ;  to 
this  is  added  500  grammes  of  alcohol  of  at  least  95  per  cent.  The  per- 
centage of  cotton  cannot  be  increased  at  pleasure,  for  with  3  per  cent, 
of  cotton,  the  collodion  becomes  already  so  thick  that  plates  are  coated 
with  it  with  difficulty;  and  when  the  cotton  is  perfectly  saturated 
with  alcohol,  500  grammes  of  ether  of  a  specific  gravity  of  0.725  is 
added;  the  bottle  is  now  well  shaken,  until  all  the  cotton  has  dis- 
solved; it  is  now  placed  for  at  least  a  week  in  a  cool  dark  place  for 
settlement ;  when  the  collodion  has  become  perfectly  clear,  it  is  de- 
canted off.  I  generally  keep  on  hand  plain  collodion  containing  two 
and  four  per  cent,  of  gun-cotton.  The  former  is  for  ordinary  collo- 
dion ;  the  latter  is  added  to  give  any  desired  consistency.  When  all 
has  dissolved,  this  mixture  is  tested  with  litmus-paper,  to  see  if  it  has 
an  acid  reaction ;  should  the  latter  be  the  case,  it  has  to  be  neutral- 
ized with  a  pinch  of  carbonate  of  soda. 

Collodion  must  be  kept  in  the  dark  in  well-corked  bottles.  Ac- 
cording to  its  preparation  it  will  keep  for  a  shorter  or  longer  space 
of  time.  Its  keeping  qualities  depend  in  a  great  measure  on  the  na- 
ture of  the  cotton. 

Half-decomposed  pyroxylin,  which  has  been  made  from  old  linen 
at  a  high  temperature,  will  not  keep  long  even  if  it  should  work  well 
at  first.  To  test  plain  collodion  for  its  keeping  qualities,  it  should  be 
well  shaken  with  dry  carbonate  of  potash ;  if  it  is  good,  it  must  re- 
main colorless  for  the  first  two  hours ;  if  it  turns  rapidly  brown,  it 
will  not  keep  long. 

The  ether  also  has  something  to  do  with  its  permanence.  It  is  often 
ozonized,  and  liberates  iodine  from  the  metals  of  iodine  that  have 
been  added. 

Such  collodion  will  work  very  intense  at  first,  but  it  will  not  keep. 
In  oxidizing,  aldehyde  and  acetic  acid  will  be  produced,  which  also 
act  injuriously. 

IODIZING  SALTS. 

The  plain  collodion,  which  is  the  bearer  of  the  picture,  may  be 
mixed  at  once  with  the  sensitive  salts  of  silver,  which  in  this  case  re- 


IODIZING  SALTS. 


95 


main  suspended  in  the  collodion.  This,  however,  is  not  generally- 
done,  but  the  iodide  and  bromide  of  silver  are  formed  in  the  film  by- 
adding  the  iodine  and  bromine  metals  to  plain  collodion,  and  by  dip- 
ping the  plate  coated  with  this  mixture  into  a  solution  of  nitrate  of 
silver,  by  double  decomposition  iodide  and  bromide  of  silver  are  pre- 
cipitated in  the  film  itself.  The  addition  of  the  metals  of  iodine  and 
bromine  to  plain  collodion  is  called  iodizing,  and  the  salts  which  are 
employed  are  called  the  iodizing  salts,  and  the  collodion,  after  being 
mixed  with  these  substances,  is  called  iodized  collodion,  or  often 
simply  salted  collodion  (the  former  expression  is,  in  so  far,  incorrect, 
as  not  only  iodine,  but  also  bromine  metals,  are  added  to  the  collo- 
dion).* 

We  will  now  consider  a  little  more  closely  the  properties  of  the 
iodizing  salts  and  the  salted  collodion.  It  is  evident  that  of  the 
numerous  iodine  and  bromine  metals  only  those  can  be  used  for  salt- 
ing collodion  which  are  soluble  in  alcohol  and  ether. 

The  following  are  employed  : 

Iodide  of  potassium  (KI),  atomic  weight  =  166.12,  is  a  salt  free 
from  water,  which  crystallizes  in  cubes  ;  it  melts  easy  at  glowing  heat ; 
when  the  temperature  becomes  higher  it  evaporates;  it  is  easily  solu- 
ble in  water;  at  12°  C,  1  part  of  iodide  of  potassium  is  dissolved  in 
0.735  water.  The  solution  of  iodide  of  potassium  dissolves  iodine  in 
considerable  quantities.  It  does  not  dissolve  readily  in  alcohol ;  1 
part  KI  requires  from  40  to  60  parts  of  strong  alcohol,  according  to 
Hardwich  180  parts  of  absolute  alcohol.  In  its  crystallized  state, 
it  does  not  change  in  the  light ;  dissolved  in  HO,  it  soon  turns  yellow 
in  the  light,  and  iodine  is  liberated.  Its  reaction  is  alkaline.  Dis- 
solved in  5  to  10  HO,  no  reaction  is  perceptible ;  but  when  a  piece  is 
moistened  with  HO,  and  placed  on  violet  litmus-paper,  the  latter  will 
after  awhile  assume  a  wine  color  (that  this  change  of  color  does  not 
take  place  at  once  is  probably  owing  to  a  decomposition).  Hardwich 
states  that  the  pure  salt  changes  color  in  the  light ;  when  this  is  not 
the  case,  it  is  owing  to  the  presence  of  a  free  alkali. 

Bromide  of  potassium,  atomic  weight  119.12,  crystallizes,  free  from 
water,  in  cubes,  the  same  as  iodide  of  potassium  ;  is  permanent  in  the 
air ;  melts  at  a  red  heat ;  dissolves  very  readily  in  water,  but  very 
slowly  in  alcohol,  so  much  so  that  it  will  precipitate  under  double 
decomposition,  when  a  saturated  alcoholic  solution  of  iodide  of  po- 
tassium is  replaced  by  the  solution  of  one  of  the  bromine  metals,  for 


*  The  reason  why  the  salts  of  bromine  are  also  added  to  the  collodion  will 
be  explained  further  on. 


96 


THE  PRACTICE  OF  PHOTOGRAPHY. 


instance,  bromide  of  cadmium.  According  to  Hardwich,  an  ounce 
of  collodion,  containing  4^  ether  and  3|  alcohol,  will  only  dissolve  \ 
grain  of  bromide  of  potasssium.  KBr  dissolved  in  10  parts  of  water 
has  a  neutral  reaction;  but  when  pieces  of  it  are  moistened  with 
water,  and  laid  on  pieces  of  litmus-paper,  its  reaction  is  decidedly 
alkaline. 

The  difficulty  with  which  iodide  and  bromide  of  potassium  dissolve 
in  water  renders  their  employment  in  iodizing  collodion  rather  diffi- 
cult ;  it  happens  not  unfrequently  that  they  will  crystallize  out  of  the 
solution,  particularly  at  a  low  temperature,  and  form  precipitates, 
which  in  the  photographic  practice  give  rise  to  spots.  I  employ  them 
only  exceptionally. 

Iodide  of  sodium  (NaI  +  4HO),  atomic  weight  =  186,  crystal- 
lizes with  4  atoms  of  water  in  small  spear-shaped  crystals  ;  decomposes 
in  the  air.  It  dissolves  very  easily  in  water,  and  quite  freely  in 
alcohol;  100  parts  of  alcohol  of  95  per  cent,  will  dissolve,  at  15°  C, 
8.33  parts  of  iodide  of  sodium.  On  account  of  its  solubility,  it  is 
preferable  to  iodide  of  potassium.  In  its  other  qualities  it  is  very 
similar  to  iodide  of  potassium.  A  great  deal  of  the  Nal  of  commerce 
is  almost  free  from  water. 

Bromide  of  sodium  (NaBr  +  4  HO),  atomic  weight  =  139,  crys- 
tallizes containing  a  certain  amount  of  water ;  it  is  not  influenced  by 
exposure  to  the  air ;  dissolves  readily  in  water,  slightly  in  alcohol, 
but  better  than  bromide  of  potassium.  The  solubility  of  the  pure 
salt  is  not  known.  In  the  presence  of  iodide  of  cadmium  100  parts 
of  alcohol  at  95°  will  dissolve  (according  to  the  amount  of  cadmium) 
0.8  to  1.3  iodide  of  sodium. 

Unfortunately  iodide  of  sodium,  as  well  as  bromide  of  sodium, 
when  purchased  commercially,  are  very  seldom  pure,  and  occasion, 
when  employed  photographically,  many  inconveniences. 

Iodide  of  ammonium  (NH4 1),  atomic  weight  =  145,  is  a  very  un- 
stable salt,  which  generally  is  half-decomposed  when  purchased ;  it 
readily  parts  with  iodine  and  becomes  yellow.  When  fresh  its  reac- 
tion is  alkaline  ;  it  dissolves  in  alcohol  much  more  readily  than  KI 
and  Nal,  and  must  be  kept  in  a  dark  place.  Its  impurities  are  very 
often  Am  O  C  02  and  S  03.  The  yellow  mass  is  made  white  again 
by  shaking  with  ether,  or  by  adding  a  drop  of  sulphate  of  ammonia  ; 
its  solubility  in  alcohol  has  caused  its  general  employment  in  photog- 
raphy. 

Bromide  of  ammonium  (N  H4  Br),  atomic  weight  —  98  ;  it  is  made 
by  the  direct  action  of  ammoniacal  gas  on  bromine ;  nitrogen  escapes 
and  N  H4  Br  remains.    It  is  a  more  constant  salt  than  N  H4 1,  and 


IODIZING  SALTS. 


97 


dissolves  more  readily  in  alcohol  than  KI  and  Nal.  100  parts  of 
alcohol  at  95°  will  dissolve  3  parts  of  NH4Br. 

Iodide  of  lithium  (Lil  +  6HO)  contains,  according  to  Rammels- 
berg,  6  equivalents  of  water ;  is  deliquescent  in  the  air,  and  turns 
yellow  ;  dissolves  readily  in  water  and  alcohol.  It  is  only  rarely 
employed  for  iodizing. 

Bromide  of  lithium  (LiBr2)  ;  its  qualities  are  not  very  well  known. 
It  dissolves,  like  Lil,  readily  in  alcohol,  and  is  only  exceptionally 
employed. 

Iodide  of  calcium  (Cal)  and  Bromide  of  calcium  (CaBr)  form  salts 
easily  soluble  in  water,  which  readily  decompose  in  the  air  by  parting 
with  carbonate  of  lime. 

Iodide  of  zinc  and  Bromide  of  zinc  form  white  crystals,  which  be- 
come liquid  when  exposed  to  the  air ;  are  soluble  in  water  and  alcohol, 
and  decompose  readily.  They  are  not  often  employed  in  photography. 
The  inclination  which  Znl  possesses  to  form  double  salts  is  interest- 
ing ;  we  mention  the  NH4  -f  Znl  and  Kal  -J-  2ZnI. 

Iodide  of  cadmium  (Cdl),  atomic  weight  =  182.7 ;  it  is  obtained 
by  heating  cadmium-foil  with  iodine  and  water ;  the  solution  yields, 
on  evaporating  it,  large  six-sided  plates.  It  can  be  fused,  and  is  free 
from  water  ;  under  the  influence  of  light  it  easily  turns  yellow ;  dis- 
solves readily  in  alcohol  and  water,  and  forms  plates  which  have  a 
lustre  like  mother  of  pearl ;  its  reaction  in  solutions  is  acid ;  exposure 
to  the  air  does  not  change  it ;  it  shows  a  tendency  to  forming  double 
salts. 


Combined  with  oxide  of  cadmium,  it  forms  iodic  oxide,  which  is 
decomposed  by  alcohol. 

Bromide  of  cadmium  (CdBr  -f-  4HO),  atomic  weight  =  171.7;  it 
is  obtained  in  the  same  way  as  iodide  of  cadmium  ;  crystallizes  with 
four  equivalents  of  water  in  needle  shape,  which  decompose  in  the 
air ;  is  easily  soluble  in  water  and  alcohol,  and  melts  and  sublimes  at 
a  high  temperature ;  it  is  apt  to  form  double  salts. 


These  double  salts  have  not  been  exactly  determined  as  yet,  but 
the  photographic  practice  seems  to  indicate  that  great  solubility  in 
alcohol  and  greater  permanence  are  the  characteristic  features.  This 


Ami  Cdl  +  2  HO  V  according  to  Croft. 
Nal  Cdl  +  6  HO  J 


KBr  +  2  CdBr  +  HO  also  KaBr  +  CdBr 
and  NaBr  +  2  CdBr  +  5  HO  (Croft). 


7 


98 


THE  PRACTICE  OF  PHOTOGRAPHY. 


is  the  reason  why  mixtures  of  cadmium  and  alkaline  salts  are  pre- 
ferred for  iodizing  collodion.  Of  all  the  iodizing  salts  those  of  cad- 
mium are  the  most  permanent.  They  would  be  employed  exclusively 
if  their  acid  reaction  would  not  somewhat  impair  the  sensitiveness  of 
the  preparations. 

ACTION  OF  THE  IODIZING  SALTS. 

When  different  kinds  of  collodion  are  mixed  with  different  iodizing 
salts  in  equivalent  proportions,  we  find  very  marked  differences  in 
their  action,  which  we  cannot  expect  a  priori,  and  which  relate,  on 
the  one  hand,  to  the  fluidity,  on  the  other  hand,  to  the  permanency 
and  sensitiveness  of  the  preparation.  Of  importance  are  :  1,  the 
physical  actions  which  the  salts  exert  on  the  collodion.  It  has  been 
found  that  the  alkaline  iodizing  salts  (potassium,  sodium,  ammonium, 
and  lithium)  make  the  collodion  limpid,  while  the  others  (Cdl,  Znl, 
CdBr)  make  the  collodion  thick  (some  collodions,  which  have  been 
prepared  with  an  excess  of  sulphuric  acid,  become,  on  the  addition 
of  iodide  of  potassium,  first  very  thick,  and  then  all  at  once  very 
limpid). 

We  notice  a  similar  tendency  of  making  collodion  very  fluid  in 
some  of  the  alkaline  carbonates,  which  are  frequently  added  to  the 
iodizing  salts.  There  are  only  four  salts  used  in  photography  which 
have  an  acid  reaction,  namely,  iodide  and  bromide  of  cadmium,  and 
iodide  and  bromide  of  zinc.  The  others,  which  have  been  mentioned 
above,  have  an  alkaline  reaction.  It  is  self-evident  that  for  the  for- 
mer a  thinner,  for  the  latter  a  thicker  collodion  should  be  selected — 
i.  e.,  one  which  contains  more  or  less  pyroxylin. 

2.  Permanence. — In  regard  to  permanence,  collodion  prepared  with 
cadmium  stands  at  the  head  of  the  list;  it  keeps  a  long  time  without 
turning  yellow,  while  alkaline  iodizing  salts,  in  solution,  decompose 
rapidly,  and  the  collodion  turns  first  yellow,  next  red,  and  becomes 
very  limpid.  The  least  stable  salt  of  the  kind  is  ammonium,  next 
follows  iodide  of  lithium,  and  finally  iodide  of  cadmium.  The 
bromine  metals  do  not  decompose  as  easily.  The  cause  of  the  red 
color  is  the  oxidation  of  the  alkaline  metals,  on  the  one  hand  by 
ozone,  which  is  frequently  contained  in  the  ether,  on  the  other  hand 
by  nitrous  acid  from  the  pyroxylin.  Sometimes  the  impurities  of 
the  salts  are  the  cause,  because  they  contain  alkaline  carbonates.  The 
permanency  of  the  collodion  is  increased  when  several  salts  are  used 
for  iodizing  it ;  it  is  probably  due  to  the  formation  of  double  salts, 
which  resist  decomposition  longer  (see  above,  Iodide  of  cadmium). 


ACTION  OF  THE  IODIZING  SALTS. 


99 


3.  A  third  point  is  the  solubility  of  the  salts.  Iodide  of  potassium, 
for  instance,  dissolves  only  very  sparingly,  and  can  only  be  used  under 
certain  conditions.  A  collodion  containing  equal  parts  of  alcohol  and 
ether  (the  former  of  0.816)  will  bear  for  every  120  parts,  1  part  of 
iodide  of  potassium  (Hardwich)  ;  but  when  we  add  iodide  of  cadmium, 
a  more  soluble  double  salt  will  be  formed,  consisting  of  almost  equal 
parts  by  weight  of  both  the  salts.  Bromide  of  potassium  dissolves 
still  more  sparingly.  Collodion  containing  ether  and  3i  alcohol 
will  not  take  more  than  J  grain  per  ounce  of  bromide  of  potassium 
(Hardwich).  A  precipitate  is  easily  formed  when  we  add  bromide  of 
cadmium  to  collodion  containing  iodide  of  cadmium.  This  is  a  second 
reason  for  rejecting  KI  and  taking  the  more  soluble  sodium  and 
ammonium  salts. 

Li  I  and  N  H*  I  dissolve  very  readily ;  but  their  tendency  to  de- 
composition destroys  the  permanence  of  a  preparation  containing  them- 
and  they  are  not  very  easily  obtained  pure.  Of  the  salts  of  bromine, 
the  best  and  most  soluble  is  bromide  of  cadmium  ;  the  next  is  bromide 
of  ammonium,  to  which  the  author  gives  the  preference.* 

4.  Finally,  the  photographic  qualities  have  to  be  considered. 
These  differences  do  not  show  themselves  much  with  freshly  iodized 
and  pure  collodions,  which  have  been  mixed  with  equivalent  quanti- 
ties of  different  iodine  and  bromine  salts  (Hardwich).  Observe  that  a 
fresh  iodide  of  potassium  gives  a  stronger  picture  than  iodide  of  am- 
monium, and  the  latter  gives  apparently  a  stronger  picture  than 
iodide  of  cadmium.  The  inferior  intensity  of  the  iodide  of  cadmium 
collodion  pictures  is  probably  explained  by  the  acid  reaction  of  the 
nitrate  of  cadmium  oxide,  formed  in  silvering.  In  course  of  time, 
however,  the  collodions  will  change,  those  containing  K  I  and  NH4I 
changing  the  most  rapidly ;  they  become  less  sensitive  and  turn  red 
and  limpid,  but  will  give,  with  extended  exposure,  sufficiently  intense 
pictures. 

The  change  in  photographic  sensitiveness  takes  place  much  more 
rapidly  simultaneously  with  an  increase  of  the  intensity,  in  the  presence  of 
organic  substances,  such  as  nitro-glucose,  grape-sugar ;  also  with  col- 
lodion which  has  been  prepared  at  a  high  temperature  and  in  a  very 
diluted  state. 


*  The  solubility  of  bromide  of  sodium  is  much  increased  by  the  presence  of 
cadmium  salts.  According  to  two  experiments,  30  parts  of  alcohol  contain- 
ing 0.7  iodide  of  cadmium  and  0.7  iodide  of  sodium  dissolved  0.233  bromide 
of  sodium.  While  30  parts  of  alcohol,  containing  1.0  iodide  of  cadmium  and 
0.4  iodide  of  sodium,  dissolved  0.317  bromide  of  sodium.  With  1.4  iodide  of 
cadmium  0.4  bromide  of  sodium  was  dissolved. 


100 


THE  PRACTICE  OF  PHOTOGRAPHY. 


A  collodion  is  called  intense,  if  on  development  it  yields  a  very 
dense  and  little  transparent  picture;  sensitive  on  the  other  hand, 
means,  when  dark  objects  (shadows,  details  of  dark  dresses,  etc.)  are 
clearly  indicated. 

Both  qualities  do  not  run  parallel ;  some  collodions  yield  a  very 
thin  picture,  but  are  very  sensitive  to  dark  rays,  while  others  work 
very  intense,  but  reproduce  only  the  brightest  parts  of  the  object  to 
be  taken. 

The  best  collodion  is  the  one  which  is  sensitive  and  intense  at  the 
same  time. 

One  often  fiuds  that  a  collodion  at  first  turns  red,  but  becomes  after- 
wards lighter.  This  is  explained  by  the  formation  of  organic  reduc- 
ing bodies,  which  absorb  the  iodine,  which  causes  the  yellow  color. 

It  only  remains  to  explain  why  generally  a  mixture  of  iodine  and 
bromine  salts  is  employed  for  salting  the  collodion. 

In  order  to  get  a  clear  understanding  about  the  main  point — the 
sensitiveness  of  the  collodion — I  undertook  a  number  of  special  ex- 
periments. I  prepared  three  different  kiDds  of  collodion,  to  which 
were  added  equivalent  quantities  of  chloride  of  cadmium,  bromide  of 
cadmium,  and  iodide  of  cadmium.  They  were  sensitized  as  usual, 
and  a  white  plaster  of  Paris  cast,  partially  covered  with  black  drapery, 
was  "  taken  "  with  the  different  collodions.  All  the  three  plates  were 
exposed  equally  long  and  developed  with  a  solution  of  sulphate  of 
iron. 

The  collodion  containing  iodine  gave  a  very  intense  picture  of  the 
white  plaster,  but  the  drapery  looked  weak,  and  the  outlines  were  in- 
distinct. 

The  collodion  containing  bromine  gave  a  clear  but  weak  picture  of 
the  plaster,  and  did  not  show  a  trace  of  the  drapery. 

The  chlorine  collodion  did  not  show  a  trace  of  the  picture.* 

According  to  the  above  the  pure  iodide  collodion  is  photographic- 
ally the  most  sensitive. 

To  complete  the  experiments  a  mixed  collodion  was  examined. 

Three  different  kinds  of  collodion  were  prepared:  1,  a  pure  iodine 
collodion ;  2,  a  collodion  containing  as  much  iodine  as  No.  1,  and 
besides  i  of  a  bromine  salt ;  3,  a  collodion  with  as  much  iodine  as 
No.  1,  and  also  J  of  a  chlorine  salt.  With  these  chemicals  the  plaster 
of  Paris  cast  and  drapery  were  taken  under  similar  circumstances. 

The  iodine  collodion  gave  again  a  very  intense  but  rather  "  washed  " 
picture  of  the  plaster,  and  very  little  detail  in  the  black  drapery. 

*  This  does  not  prove  the  photographic  insensibility  of  the  chloride  of  silver 
collodion,  as  with  longer  exposure  a  picture  would  certainly  be  the  result. 


ACTION  OF  THE  IODIZING  SALTS. 


101 


The  bromo-iodized  collodion  and  the  chloro-iodized  collodion  gave  a 
less  intense,  but  a  clearer  picture  of  the  plaster,  and  much  more  detail 
in  the  black  drapery.  Some  dark  folds  in  the  latter,  which  were 
scarcely  visible  in  the  picture  taken  with  iodized  collodion,  became 
plainly  visible  with  the  mixed  collodion. 

Hence,  it  follows, 

Pure  collodion  mixed  with  iodine  is  more  sensitive  for  stro?ig  lights 
(plaster,  etc.)  ;  mixed  collodion  is  more  sensitive  for  feeble  lights.  The 
latter  is  consequently  employed  when  we  wish  to  secure  details  in  the 
shadows. 

This  refers,  however,  only  to  wet  plates  prepared  in  the  ordinary 
way  in  the  silver  bath,  and  for  acid  development. 

Dr.  Schultz-Sellack  explains  the  greater  sensitiveness  for  shadow, 
perceptible  in  mixed  collodions,  by  their  greater  sensitiveness  for  colors. 
In  the  spectrum,  iodide  of  silver  collodion  is  sensitive  only  for  violet 
and  indigo.  Iodo-bromide  of  silver  collodion,  on  the  other  hand,  is 
sensitive  for  blue  and  green  also.  The  shadows  which  receive  their 
light  by  reflection  from  colored  bodies  are  cok>red  also — i.  e.,  they 
contain  more  green  and  blue  rays  than  violet,  and  hence  their  greater 
action  on  iodo-bromide  of  silver.  This  theory  is  not  free  from  objec- 
tion. The  action  of  green  and  blue  rays  on  iodo-bromide  of  silver 
does  not  take  place  immediately,  but  only  after  a  longer  exposure,  while 
the  greater  sensitiveness  for  shadows  manifests  itself  instantaneously. 
The  author  demonstrated  further,  that  a  lens  with  a  very  small  dia- 
phragm, in  other  words,  a  lens  feeble  in  light,  furnishes  with  iodide  of 
silver  a  weaker  picture  of  an  India-ink  drawing  than  with  bromide 
of  silver.  In  this  instance  we  cannot  speak  of  color,  and  the  author 
supposes  that  light  has  to  act  for  a  certain  length  of  time  before  it 
overcomes  the  inertia  of  the  atoms,  and  produces  such  vibrations  as 
to  separate  them.  (See  also  the  action  on  chlorhydrogen  gas  in  the 
chapter  on  Chemical  Meteorology.) 

The  initial  action  takes  place  certainly  sooner  with  iodo-bromide  of 
silver  than  with  iodide  of  silver.  In  the  mixed  collodion  the  more 
easily  reducible  bromide  of  silver  induces  the  slower  iodide  of  silver 
to  a  quicker  decomposition,  and  it  is  the  latter  which,  owing  to  its 
greater  capacity  to  darken  with  the  developer,  makes  this  action  pho- 
tographically visible. 

It  was  formerly  generally  supposed,  that  the  sensitiveness  of  a  col- 
lodion increased  with  the  amount  of  salt  contained  in  it.  This,  how- 
ever, is  by  no  means  correct.  The  experiments  of  the  author  demon- 
strated that  by  increasing  the  amount  of  salt  from  1J  to  2.2  per  cent., 
no  perceptible  increase  of  sensitiveness  took  place;  that  with  a  still 


102 


THE  PRACTICE  OF  PHOTOGRAPHY. 


greater  percentage  of  salt  the  collodion  worked  with  greater  intensity, 
but  became  less  sensitive,  and  part  of  the  iodide  of  silver  was  thrown 
out,  forming  yellow  lines. 

Zettnow  demonstrated  later  that  the  increase  of  the  salts  increases 
the  sensitiveness  only  up  to  a  certain  point,  and  that  a  further  ad- 
dition of  salt  lessens  the  sensitiveness  (Photographische  Mittheilungm, 
vol.  8,  page  300).  According  to  his  experiments  the  sensitiveness  in- 
creased up  to  a  percentage  of  bromo-iodine  salts  of  1^  per  cent.,  and  up 
to  If  remained  stationary.  The  amount  of  pyroxylin  in  the  collo- 
dion is  of  much  more  importance. 

Zettnow  recommends  the  above  proportions  as  the  most  practical. 
Different  quantities  of  pyroxylin  give,  however,  different  results,  as  is 
shown  by  the  author's  experiments.  In  regard  to  the  proportion  of 
iodine  to  bromine,  the  author  found  5  equivalents  of  iodine  to  1 
equivalent  of  bromine  the  most  advantageous  for  the  making  of  sen- 
sitive collodion  (Photographische  Mittheilungen,  vol.  9,  page  239). 

PREPARATION  OF  SALTED  COLLODION. 

The  plain  collodion  must  be  mixed  with  the  metals  of  iodine  and 
bromine.  Many  photographers  add  the  latter  to  the  oily  liquid. 
This  is  impractical ;  generally  the  salts  contain  small  traces  of  im- 
purities, which  settle  only  very  slowly  from  the  collodion  and  neces- 
sitate a  tedious  decantation. 

It  is  therefore  much  more  practical  to  dissolve  the  salts  of  iodine 
and  bromine  by  themselves  in  alcohol,  and  to  add  them  after  a  care- 
ful, if  possible,  double  filtration,  to  the  decanted  plain  collodion. 

Such  a  solution  of  the  salts  of  iodine  and  bromine  in  alcohol  is 
called  an  iodizer  or  sensitizer. 

Of  especial  importance  is  the  selection  of  the  sensitizing  salts.  As 
for  the  formulae  that  have  been  recommended  for  this  purpose,  their 
name  is  legion.  It  is  not  my  intention  here  to  furnish  a  collection  of 
formulse,  although  amongst  the  many  recipes  there  are  a  great  many 
good  ones.  When  we  try  the  collodions  of  different  manufacturers 
and  photographers,  we  will  notice  in  their  qualities  very  perceptible 
differences. 

Some  work  soft,  others  weak — i.  e.f  they  furnish  pictures  with  much 
detail  in  the  shadows,  but  few  high  lights  ;  others  work  hard,  but  bril- 
liant. 

Some  will  yield  an  intense,  others  a  thin  picture.  And  still  all 
these  widely  different  collodions  will  give  good  results  in  the  hands 
of  a  person  who  knows  how  to  handle  them. 


PREPARATION  OF  SALTED  COLLODION. 


103 


It  is  possible  to  secure  with  a  feeble  working  collodion  a  brilliant 
picture  by  an  illumination  rich  in  contrasts ;  and,  vice  versa,  when  we 
have  a  collodion  which  yields  too  much  contrast,  we  may,  by  proper 
illumination,  secure  a  harmonious  picture.  Also  by  the  proper  selec- 
tion of  the  developer  many  errors  may  be  equalized. 

But  any  one  who  intends  to  apply  the  same  manner  of  working 
to  all  the  different  collodions,  will  condemn  much  as  bad  which,  in 
more  skilful  hands,  would  secure  good  results. 

On  the  other  hand,  we  cannot  deny  that,  especially  in  this  article, 
considerable  capital  has  been  made  out  of  the  ignorance  of  photogra- 
phers, and  collodion  with  the  strongest  sensitizers — lately  even  casein 
and  rubidium — have  been  recommended  as  the  photographer's  "  phil- 
osopher's stone." 

On  the  presence  of  bromine  depends  the  sensitiveness  for  dark  rays 
— i.  e.,  details  in  the  shadows  and  softness  ;  while  on  the  presence  of 
the  salts  of  iodine  depends  the  sensitiveness  for  bright  rays — i.  e.,  the 
intensity  of  the  high  lights ;  from  this  the  conclusion  has  been  rather 
rashly  drawn  that  collodion  works  softer  according  to  the  proportion 
of  bromine  which  it  contains ;  but  this  is  certainly  not  the  case. 

Late  experiments  of  the  author  have  demonstrated  that  a  collodion 
containing  5  equivalents  of  iodide  of  cadmium  and  one  equivalent  of 
bromide  of  cadmium  works  softer  and  is  more  sensitive  than  a  collo- 
dion -containing  double  and  four  times  the  quantity  of  bromide  of 
cadmium  in  proportion  to  the  iodide  of  cadmium  employed. 

For  testing  collodion  nothing  is  better  than  a  plaster  of  Paris  cast 
surrounded  by  black  drapery. 

For  comparative  experiments,  the  most  exact  coincidence  in  regard  to 
light,  silver  bath,  and  developer,  is  of  the  greatest  importance. 

The  following  are  the  formulae  which  we  can  recommend. 

(a.)  Sodium  collodion  of  Dr.  Vogel. 

Iodide  of  cadmium,  1  gramme. 

Iodide  of  sodium,  0.4  " 

Bromide  of  sodium,  0.3  " 

dissolved  in  30  cubic  centimetres  of  alcohol,  filtered,  and  one  volume  is 
mixed  with  three  volumes  of  plain  collodion  of  the  following  composi- 
tion. 

Alcohol,  50 

Ether,  50 

Cotton,    .       .       .       .  .  2 

This  corresponds  with  2-2 J  per  cent,  of  salt. 


104  THE  PRACTICE  OF  PHOTOGRAPHY. 


(b.)  Equivalent  collodion  of  Dr.  Vogel. 
18  grammes  of  iodide  of  cadmium,  dissolved  in  270  grammes  of  alcohol. 
17  grammes  of  bromide  of  cadmium,  dissolved  in  270  grammes  of  alcohol. 

Each  solution  is  filtered  by  itself,  and  5  volumes  of  the  solution  of  the 
iodine  salt  are  mixed  with  1  volume  of  bromine  solution,  and  18  parts 
of  2  per  cent,  plain  collodion. 

We  add  the  following  formulae  of  well-known  photographers. 

(c.)  Loescher  &  Petsch  collodion. 

Cotton,  34  grammes. 

Dissolved  in 

Ether,   1560  " 

Alcohol,   780  " 

To  which  is  added 

Iodide  of  ammonium,      .       .       .       .16  grammes. 
Bromide  of  cadmium,      .        ...    16  u 
Iodide  of  potassium,        .       .       .       .16  " 
Iodide  of  cadmium,  6.6  " 

These  salts  are  first  dissolved  in  780  grammes  of  alcohol,  and  filtered. 
(d.)  Kurtz  collodion. 


Ether,  . 
.   Alcohol,  . 

Iodide  of  ammonium, 
Bromide  of  cadmium, 
Bromide  of  potassium, 

Better  3.64  bromide  of  sodium,  or  2.5  brom 
9.37  grammes. 


450  grammes. 
450  " 

6  " 

3.12  » 

3.12  " 

de  of  ammonium,  cotton 


We  recommend  here  also  to  dissolve  the  above  salts  in  i  of  the  re- 
quired alcohol,  to  filter,  and  to  add  it  to  the  decanted  collodion,  which 
contains  the  balance  of  the  alcohol-ether  and  cotton. 

As  soon  as  the  sensitizing  salts  have  been  added  to  the  plain  collo- 
dion, it  should  be  well  shaken  for  a  few  minutes,  and  left  to  stand 
for  at  least  twenty-four  hours,  with  cadmium  collodion  for  two  days, 
when  the  collodion  will  give  its  best  results.  Perfect  cleanliness  of  the 
bottles  is  to  be  observed. 

For  travelling  purposes  cadmium  collodions  (see  above,  b),  are 
recommended  because  they  keep  longer  with  a  good  portrait  practice. 
Where  the  keeping  qualities  on  account  of  the  rapid  consumption  are 
of  less  moment,  collodion  with  ammonium  salts  may  be  used  as  well. 
If  in  any  of  the  formulae  we  wish  to  substitute  another  salt  for  an 


PREPARATION  OP  SALTED  COLLODION.  105 

iodide  or  bromide,  this  must  be  done  in  the  proportion  of  their  atomic 
weight ;  for  instance, 

166  dry  iodide  of  potassium  corresponds  with  186  iodide  of  sodium, 
145  iodide  of  ammonium,  182  iodide  of  cadmium,  134  iodide  of  lithium 
(free  from  water). 

119  bromide  of  potassium  corresponds  with  139  bromide  of  sodium, 
98  bromide  of  ammonium,  172  bromide  of  cadmium. 

These  proportions  refer  only  to  salts  chemically  pure.  For  the  iodiz- 
ing salts  of  the  trade  the  proportions  are  somewhat  different. 

For  instance,  10  bromide  of  cadmium  corresponds  with  6  bromide  of 
ammonium,  6.8  bromide  of  lithium,  9.3  iodide  of  ammonium. 

Generally  the  freshly  mixed  salts  soon  turn  yellow,  although  the 
salts  themselves  are  colorless.  Later  the  yellow  collodion  sometimes 
becomes  colorless  again;  this  is  no  doubt  due  to  organic  substances, 
which  absorb  the  iodine,  the  cause  of  the  yellow  color. 

Generally,  freshly  mixed  collodion  will  soon  turn  yellow,  even  if  the 
sensitizing  salts  are  colorless.  Collodion  containing  salts  of  cadmium 
remains  white  longer  than  any  other.  Some  collodions  have  a  ten- 
dency to  fogging  previous  to  their  turning  yellow.  This  can  be 
avoided  by  making  the  nitrate  bath  acid,  or  by  adding  to  the  collo- 
dion a  few  drops  of  tincture  of  iodine  (which 
will  at  once  impart  a  yellow  color  to  it).* 
A  collodion  rich  in  alcohol  is  more  apt  to 
fog  than  a  collodion  rich  in  ether. 

Some  collodions  will  settle  very  slowly; 
after  standing  for  months  they  will  still  give 
streaked  and  spotted  plates.  This  is  particu- 
larly the  case  when  they  have  been  made  at 
a  low  temperature.  Such  collodion  must  be 
filtered:  this  is  a  tedious  operation,  which 
has  to  be  performed  with  an  apparatus  es- 
pecially designed  for  this  purpose.  The  ap- 
paratus has  a  funnel,  T,  Fig.  58,  which  fits 
exactly  into  the  neck  of  the  bottle ;  the  fun- 
nel can  be  closed  by  a  ground-glass  stopper, 
s;  washed  cotton  is  loosely  packed  around 
the  glass  tube,  r.  The  collodion  is  placed 
in  the  funnel  and  drops  slowly  into  the 
lower  bottle,  while  the  air  from  the  same  escapes  into  the  upper  one 


*  Tincture  of  iodine  is  made  by  dissolving  1  part  iodine  in  25  parts  of 
alcohol. 


106 


THE  PRACTICE  OF  PHOTOGRAPHY. 


by  the  small  glass  tube.  The  upper  stopper,  s,  prevents  the  evapor- 
ation of  the  collodion. 

How  to  use  and  how  to  take  care  of  the  collodion  will  be  explained 
in  a  subsequent  chapter. 

2.  THE  NITRATE  OF  SILVER  BATH. 

The  functions  of  the  bath  are  to  make  the  collodion  film  "  sensi- 
tive " — i.  e.,  to  change  the  iodine  and  bromine  metals  into  iodide  and 
bromide  of  silver.  If  we  mix  a  solution  of  iodine  or  bromine  salt 
with  a  solution  of  silver,  iodide  or  bromide  of  silver  will  be  precipi- 
tated. Any  silver  solution  may  be  used  for  this  purpose,  but  for  pho- 
tography nitrate  of  silver  is  the  best,  because  it  dissolves  the  most 
readily  in  water,  aud  is  obtainable  most  pure.  Commercially  it  occurs 
in  two  different  forms,  the  fused  nitrate  of  silver  in  sticks  and  the 
crystallized. 

In  former  times  a  diluted  solution  of  silver  1 : 16  to  1  :  20  was  used 
for  the  sensitive  bath,  and  it  is  in  fact  suitable  for  that  purpose  still. 
But  it  is  not  advisable,  however,  to  work  with  so  weak  a  solution  of 
silver,  for  the  perfect  sensitizing  of  the  plates  progresses  only  very 
slowly,  and  if  the  collodion  contains  a  great  deal  of  iodine  and  bro- 
mine, this  will  retard  it  still  more ;  besides  the  bath  loses  with  every 
plate  a  certain  quantity  of  silver,  and  will  soon  be  exhausted  when 
the  original  percentage  is  very  small. 

Another  point  is  to  be  observed, — the  solubility  of  iodide  of  silver 
in  a  solution  of  nitrate  of  silver.  This  causes  the  so-called  "  eating 
away  "  of  the  film  in  a  newly  made  bath,  and  to  prevent  that,  one 
can  either  place  into  a  freshly  made  bath  a  coated  plate,  and  let  it 
remain  in  it  over  night,  or  better,  add  at  once  a  salt  of  iodine,  which 
causes  the  formation  of  iodide  of  silver,  and  lessens  the  capacity  of 
the  bath  to  dissolve  it  out  of  the  film. 

I  always  use  for  the  bath  the  neutral  crystallized  nitrate  of  silver; 
I  never  employ  the  fused  nitrate,  as  it  frequently  contains  silver  com- 
bined with  nitrous  acid,  which  often  gives  rise  to  great  annoyances. 

I  dissolve 

100  parts  of  nitrate  of  silver  in 
1000      "       distilled  water, 

and  add  25  parts  of  a  solution  containing  1  part  of  iodide  of  potas- 
sium in  100  parts  of  water.  I  add  1  drop  of  nitric  acid  to  1  ounce  of 
silver  salt  acid ;  only  when  a  plate  prepared  in  it  appears  veiled  we 
add  more ;  diluted  nitric  acid  is  then  added  drop  by  drop  (1  part  of 
nitric  acid,  5  parts  of  water)  ;  but  only  just  enough  to  make  the  veil 


THE  DEVELOPER. 


107 


disappear.  Mr.  Black,  the  well-known  photographer  of  Boston,  uses 
a  bath  by  far  more  acid,  but  we  believe  that  such  an  acid  bath  affects 
the  plate-holder  injuriously,  not  to  mention  that  the  film  leaves  the 
glass  very  easily  when  the  bath  is  very  acid.  I  do  not  add  acetic 
acid  to  the  bath,  as  it  is  apt  to  give  rise  to  the  formation  of  crystals 
of  acetate  of  silver;  these  are  very  sparingly  soluble  in  the  bath  so- 
lution, and  precipitate  themselves  on  the  plate  in  the  form  of  spears, 
grains,  or  spots.  The  addition  of  sugar  of  lead,  the  metals  of  bro- 
mine, and  similar  salts,  which  has  frequently  been  recommended,  is 
perfectly  superfluous.  It  must  be  mentioned  here,  that  iodide  of 
silver  is  less  soluble  in  warm  solutions  of  silver  than  in  cold  ones, 
therefore  it  happens  in  hot  weather,  that  it  precipitates  it  and  causes 
the  so-called  pinholes.  The  bath  should  therefore  be  kept  cool  in  sum- 
mer ;  the  best  temperature  is  66°  Fahrenheit. 

3.  THE  DEVELOPER. 

As  developer  for  the  negative  process,  a  solution  of  sulphate  of 
iron  is  now  generally  employed.  This  precipitates  the  silver  from  its 
solutions  as  a  fine  metallic  powder,  and  this  precipitate  is  formed 
also  when  we  pour  an  iron  solution  on  a  collodion  plate  which  is  still 
wet  from  adhering  silver  solution.  When  this  silver  solution  is  not 
present,  for  example,  when  we  wash  a  plate  before  developing  it, 
sulphate  of  iron  will  not  develop  a  picture.  This  is  the  reason  why 
with  dry  plates,  when  the  silver  solution  is  wanting  we  have  to  add  it 
in  order  to  develop.*    In  place  of  sulphate  of  iron  we  may  employ 


*  Only  alkaline  development,  of  which  we  will  speak  later,  makes  an  ex- 
ception with  an  old  bath  alcohol  as  above. 

The  peculiarities  of  glacial  acetic  acid  and  sulphate  of  iron  have  been  dis- 
cussed before. 

In  place  of  the  expensive  glacial  acetic  acid,  we  may  as  well  take  a  small 
quantity  of  sulphuric  acid.  A  developer  of  this  kind  we  have  used  for  years  ; 
we  take 

1200  grammes  water, 

60       "       sulphate  of  iron, 

3       "       sulphuric  acid, 
46       »  alcohol. 

For  reproductions,  one-half  the  quantity  of  sulphate  of  iron  is  used. 

In  place  of  the  sulphate  of  iron  the  sulphate  of  iron  and  ammonia  is  some- 
times used  ;  five  parts  sulphate  of  iron  correspond  with  seven  parts  of  iron  and 
ammonia.  This  developer  keeps  for  a  much  longer  time  than  the  other,  which 
latter  has  to  be  made  once  a  week. 

The  consumption  of  developer  per  TL  square  metres  =  one  square  foot,  is 
200-300  cubic  centimetres  or  grammes. 


108  THE  PRACTICE  OF  PHOTOGRAPHY. 

any  other  reducing  agent  as  pyrogallic  acid,  but  for  wet  plates  sul- 
phate of  iron  is  preferable.  The  precipitate  forms  only  on  those 
parts  of  the  plate  on  which  the  light  has  fallen,  and  thus  creates  the 
picture. 

In  order  that  the  precipitate  may  not  form  too  rapidly  and  cause 
irregular  deposits  over  the  whole  plate,  a  diluted  solution  of  sulphate 
of  iron  is  used.    We  also  add  acid. 

Tom  give  acidity  to  the  developer,  acetic  acid  (so-called  glacial 
acetic  acid)  is  generally  used. 

According  to  later  investigations  of  the  author,  acid  has  more  the 
property  to  maintain  the  developer  clear  (a  neutral  developer  soon 
becomes  turbid  and  deposits  base  oxide  of  iron),  than  to  retard  the 
formation  of  a  precipitate.  The  usually  added  acetic  acid  exercises 
still  another  influence ;  it  makes  the  developer  flow  readily  over  the 
collodion  film.  Acetic  acid  is  a  substance  similar  to  alcohol,  and  it 
facilitates  the  adhesion  of  water  to  the  collodion.  A  pure  watery 
developer  is  generally  repelled  by  the  collodion  film  and  causes  spots. 

With  an  old  bath  containing  much  alcohol,  this  occurs  more  readily 
than  with  a  new  one.  For  this  reason  alcohol  is  generally  added  to 
the  developer. 

For  pictures  with  half  tones  a  concentrated  developer  is  used  ;  for 
reproductions  we  work  with  a  diluted  developer. 
We  take 

(a.)  As  developer  for  portraits  and  landscapes. 

6  parts  of  sulphate  of  iron, 
3       "      acetic  acid  (glacial), 
100       "  water. 

When  the  nitrate  bath  is  old  we  add  two  parts  of  alcohol.  The  water 
does  not  need  to  be  distilled.  Ordinary  river  water  or  spring  water, 
provided  it  does  not  contain  salts  in  too  large  a  proportion,  is  suffi- 
cient. 

(b.)  Developer  for  reproducing  line  engravings. 
2%  parts  sulphate  of  iron, 
3-4    "    glacial  acetic  acid, 
100    "  water. 

4.  THE  INTENSIFIER. 

In  many  cases  the  developed  picture  is  too  weak  for  printing  pur- 
poses; its  strength  must  then  be  increased  by  intensifies ;  this  is 
done  by  pouring  on  the  plate  silver  solution  mixed  with  a  reducing 
substance,  as,  for  instance,  sulphate  of  iron,  or  pyrogallic  acid.  From 


THE  INTENSIFIED 


109 


this  mixture  silver  in  a  powdered  state  will  precipitate,  and  is  attracted 
by  the  silver  molecules  of  the  developed  picture,  and  increase  its  in- 
tensity. 

As  principal  intensifier  a  mixture  of  acid  solution  of  silver  com- 
bined with  a  reducing  liquid  is  used.  For  the  latter  a  solution  of 
pyrogallic  acid  is  generally  liked  in  the  presence  of  acid  ;  it  works 
slowly,  very  clean,  and  gives  a  heavy  film.  But,  like  the  developer, 
when  dissolved  in  water,  it  will  not  keep  long,  as  it  absorbs  oxygen 
and  turns  brown.  The  alcoholic  solution,  however,  will  keep  for 
years.  As  the  weighiug  of  pyrogallic  acid  is  more  troublesome  than 
measuring  it,  I  generally  prepare  a  stock-bottle  for  that  purpose : 
take 

1  part  of  pyrogallic  acid, 
10  parts  of  alcohol. 

Dissolve  and  filter.  "When  well  corked  this  solution  will  keep  for  an 
indefinite  length  of  time.  For  use,  4  cubic  centimetres*  are  diluted 
to  100  cubic  centimetres  with  water.  Immediately  before  use  a  small 
quantity  of  it  is  mixed  with  an  equal  volume  of  the  following  silver 
solution  : 

2  parts  of  nitrate  of  silver, 

3  "       citric  acid, 
100     "  water. 

This  silver  solution  will  keep  from  two  to  five  weeks. 

In  summer-time,  or  when  the  pyrogallic  acid  (which  sometimes 
happens)  is  more  energetic,  it  will  be  advisable  to  take  four  parts  of 
citric  acid  instead  of  three.  In  winter-time,  when  the  reduction 
should  prove  too  slow,  the  quantity  may  be  reduced  to  one  part.  For 
the  reproduction  of  line  engravings,  the  intensifier  should  be  kept 
very  acid,  in  order  to  keep  the  lines  clear. 

The  iron  intensifier  deserves  the  same  recommendation  as  the  pyro- 
gallic acid.  In  the  hands  of  inexperienced  persons  it  is  apt  to  give 
rise  to  spots ;  but  it  has  the  advantage  that  it  does  not  require  a 
washing  of  the  plate  before  intensifying,  and  when  the  proportions 
are  correct  it  works  more  rapidly. 

We  take  the  above  developer  (see  above)  and  mix  it  with  an  equal 
quantity  of  the  annexed  solution  of  citrate  of  silver : 

2  parts  of  nitrate  of  silver, 

3  "      citric  acid, 
2-3      "  alcohol, 
100      "  water. 


*  1  cubic  centimetre  =  17  minims. 


110 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Alcohol  is  ODly  added,  that  the  intensifier  flows  easier  over  the  film. 
When  the  intensifier  does  not  flow  evenly  over  the  film  spots  will  be 
the  result. 

The  other  numerous  intensifies,  which  have  frequently  been  recom- 
mended, we  cannot  mention  here  ;  many  of  them  are  interesting,  but 
they  have  not  proved  themselves  as  possessing  the  same  practical  ad- 
vantages as  those  which  we  have  mentioned  above.  Some  of  them, 
which  are  valuable  for  some  especial  branches  of  photography,  we 
will  mention  further  on. 

5.  FIXING. 

From  the  developed  and  intensified  picture  we  must  remove  the 
sensitive  material,  iodide  and  bromide  of  silver — on  the  one  hand,  in 
order  to  make  the  plate  transparent ;  on  the  other  hand,  to  protect  it 
against  further  changes  through  the  influence  of  light ;  we  take  either 
a  solution  of 

1  part  of  hyposulphite  of  soda, 
4  to  5  parts  of  water, 

or, 

1  part  of  cyanide  of  potassium, 
25  parts  of  water. 

The  solution  of  "hypo"  will  keep  for  several  days.  The  solution 
of  cyanide  of  potassium  decomposes  rapidly,  and  is  transformed  into 
potassium  formate. 

In  the  atelier,  where  an  abundance  of  water  is  constantly  at  hand, 
we  use  hyposulphite  of  soda  ;  but  where  the  supply  of  water  is  limited, 
when  travelling,  etc.,  we  use  cyanide  of  potassium. 

The  latter  also  dissolves  the  silver  of  the  picture,  and  destroys, 
when  it  is  not  quickly  removed  by  washing,  the  delicate  half-tones  of 
the  picture. 

6.  THE  VARNISH. 

The  finished  picture  requires  a  covering  to  protect  it  against  injury 
by  mechanical  influences. 

Formerly  a  concentrated  solution  of  gum  Arabic  was  used  for  this 
purpose.  This  would  be  sufficient  when  only  a  limited  number  of 
prints  are  to  be  taken  from  the  negative,  and  when  the  plate  is  not  to 
be  kept  for  any  length  of  time.  Plates  which  must  be  kept  should 
be  covered  with  a  solution  of  a  rosin  in  alcohol,  consisting  principally 
of  shellac.    There  are  as  many  varnish  recipes  as  there  are  collodion 


GLASS  PLATES. 


Ill 


formulae  ;  but  nowadays  it  is  generally  best  to  buy  the  varnish  ready 
made  from  the  stockdealer. 

To  those  who  wish  to  prepare  it  themselves  we  recommend  the  fol- 
lowing recipe : 

3  parts  white  shellac, 
8     "  sandarac, 
40     »   alcohol  of  95°. 

Kilburn  recommends  a  varnish  which  is  said  not  to  split  or  tear. 

Alcohol,       .....    1220  grammes. 
Shellac  (light  yellow), .       .       .     180  " 
Sandarac,  22  " 

To  thirty  grammes  of  this  solution  one  to  two  drops  of  castor-oil 
are  added  ;  this  makes  the  varnish  softer.  With  this  varnish  the  nega- 
tive is  in  an  hour's  time  ready  for  the  printing-frame. 

Sometimes  the  varnish  affects  the  collodion  film  injuriously ;  this  is 
obviated  by  adding  one  per  cent,  of  water.* 

7.  GLASS  PLATES. 

The  glass  plates  form  a  most  important  substratum  for  carrying 
the  collodion  film  in  photography,  and  are  used  in  enormous  quanti- 
ties. They  require  some  preparation  before  they  are  suited  for  the 
delicate  manipulations  of  the  photographic  processes.  Conditions  for 
their  employment  are, 

a.  As  nearly  as  possible  perfect  transparency,  so  as  to  permit  the 
light  to  pass  through  unchecked  in  the  printing  process.  The  white 
and  clear  plates  always  have  the  preference  over  green  glass,  or  that 
full  of  bubbles. 


*  Varnishes  containing  turpentine  generally  have  this  propensity. 

The  consumption  of  varnish  per  ^  square  metre  =  1  square  foot  is  7£ 
cubic  centimetres  or  grammes. 
(     An  important  quality  of  the  varnish  is  whether  it  takes  lead-pencil  marks 
readily  or  not,  i.  e.,  whether  the  plate  can  be  retouched. 

Sometimes  a  negative  is  coated  with  two  films  of  varnish.  On  the  first  film, 
which  bears  the  retouch,  a  second  one  is  poured  in  order  to  protect  the  lead- 
pencil  lines.  The  second  film  must  not  dissolve  the  first.  We  take  for  it 
amber  varnish.  To  make  it  we  melt  yellow  amber  carefully  in  a  covered 
dish,  and  dissolve  in  benzine.  The  solution  requires  sometimes  more  some- 
times less  benzine. 

Others  coat  the  finished  negative  with  a  solution  of  gum  Arabic  of  the 
strength  1  :  10.  When  dry,  the  retouch  is  laid  on  this  film  and  protected  by  a 
coat  of  varnish. 


112 


THE  PRACTICE  OF  PHOTOGRAPHY. 


b.  Smoothness. — Glass  plates  which  are  *  not  absolutely  level,  will 
not  make  perfect  contact  with  the  plane  of  the  picture  in  the  camera, 
and  still  worse  in  the  printing-frame.  In  the  latter  they  are  apt  to 
break. 

c.  Cleanliness  of  the  surface. — We  generally  find  two  kinds  of  pho- 
tographic glass  in  the  market — the  so-called  Rhenish  glass  and  plate- 
glass.  The  former  is  a  more  greenish  and  not  always  exactly  plane 
and  smooth  kind  of  glass  ;  it  is  made  in  the  same  way  as  window- 
glass;  it  is  first  blown  and  afterwards  flattened  out.  The  other  is 
blown  also,  but  it  is  afterwards  ground,  in  order  to  give  it  a  perfectly 
plane  surface. 

For  smaller  pictures,  the  ordinary  glass  is  good  enough,  particularly 
when  in  its  manufacture  attention  has  been  given  to  flatten  it  with 
great  care,  and  to  store  it  in  a  clean  place. 

But  when  we  require  very  plane  plates,  the  much  more  expensive 
plate-glass  should  be  taken ;  for  instance,  for  large  pictures  and  re- 
productions, which  have  to  be  mathematically  correct.  The  surface 
of  the  glass  requires  attention.  The  ordinary  Rhenish  glass  is  harder 
than  plate  glass,  and  less  exposed  to  injury  from  mechanical  or  chemical 
causes.  Glass  resists  chemical  influences  much  less  than  is  generally 
supposed.  Pulverized  glass,  when  boiled  with  water,  gives  out  a  con- 
siderable quantity  of  salt ;  even  when  a  small  quantity  of  water  is 
evaporated  on  a  glass  plate,  we  notice  sometimes  that  the  surface  is 
attacked  by  it.  Solutions  of  salt  exercise  a  still  greater  influence, 
and  we  frequently  notice  that  drops  of  water,  which  have  dried  on  the 
glass,  and  salt  solutions,  leave  an  indelible  stain. 

We  must  convince  ourselves  that  the  plates  are  of  suitable  size,  and  will 
fit  in  the  plate-holder. 

The  photographer  buys  his  plates  generally  of  suitable  size,  and 
very  often  they  are  packed  with  pieces  of  printed  paper  between  them. 
This  is  a  bad  practice,  for  the  printer's  ink  is  apt  to  leave  greasy  spots 
on  the  plate,  and  sometimes  the  print  can  be  read  on  the  glass  by 
breathing  on  it.  Strips  of  blotting-paper,  for  separating  the  plates 
from  each  other,  are  much  preferable. 

The  rough  edge  must  be  removed,  as  it  would  tear  the  cloth  in 
cleaning  the  plates,  and  is  apt  to  injure  the  hands;  this  is  easiest 
done  by  drawing  a  flat  file  over  the  edge,  or  by  rubbing  the  edges  of 
two  plates  against  each  other.  The  splinters  should  be  removed  at 
once,  as  they  will  scratch  the  glass. 

The  greatest  cleanliness  in  the  treatment  of  glass  plates  is  a  condition  of 
primary  importance. 


THE  PHOTOGRAPHIC  OPERATIONS. 


113 


All  the  plates  require  very  careful  cleaning.  The  nature  of  the 
cleaning  is  partly  chemical,  partly  mechanical. 

The  plate  is  dipped  for  a  few  hours  in  a  solution  of  either 

1  part  of  raw  nitric  acid, 
1      "  water, 

which  is  kept  in  a  dish  ;  or, 

1  part  of  bichromate  of  potash, 
1      "      English  sulphuric  acid, 
12     11  water. 

The  latter  mixture  is  recommended  by  M.  Carey  Lea.  It  destroys 
organic  substances  with  great  energy.  Attention  should  be  paid, 
however,  to  the  fact  that  crystals  of  chromate  of  alum  are  apt  to  form 
and  settle  on  the  plates ;  when  this  takes  place  the  mixture  must  be 
renewed,  as  it  has  become  useless. 

I  generally  use  nitric  acid. 

When  a  plate  is  to  be  used  at  once,  it  should  be  rubbed  carefully 
on  both  sides,  stroke  by  stroke,  with  a  rag  dipped  in  the  acid ;  after 
resting  for  a  few  minutes,  it  should  be  well  washed  with  water,  assist- 
ing with  the  hands. 

The  plates  in  order  to  drain  are  placed  on  pieces  of  blotting-paper, 
and  finally  rubbed  dry  with  a  towel  or  Canton  flannel,  which  is  kept 

EXCLUSIVELY  FOR  THIS  PURPOSE. 

Some  operators  recommend  cleaning  the  plates  with  caustic  pot- 
ash or  cyanide  of  potassium.  A  solution  of  the  strength  of  about 
1 :  10  is  rubbed  on  the  plate  with  a  linen  swab  ;  the  plate  is  then 
washed  and  dried  as  described  above. 

A  number  of  cleaned  plates  must  be  ready  before  photographic 
operations  are  commenced. 

This  cleaning  should  be  done  with  the  greatest  care,  as  a  plate  which 
is  not  previously  well  cleaned  can  never  be  brought  into  the  proper  condi- 
tion by  rubbing  it  with  chamois  leather  alone. 

It  must  not  be  neglected  to  clean  the  rough  edges  also ;  this  is  very  often 
overlooked  and  causes  stains  and  dirty  margins  in  the  pictures. 

SECTION  II. 
THE  PHOTOGRAPHIC  OPERATIONS. 

When  the  preliminary  work  which  has  been  described  in  the  pre- 
vious chapter  has  been  performed  in  the  laboratory  and  in  the  atelier, 

8 


114 


THE  PRACTICE  OF  PHOTOGRAPHY. 


the  execution  of  the  process  may  commence.  But  we  must  first  con- 
vince ourselves  that  nothing  is  wanting. 

Nothing  happens  more  frequently  to  the  beginner  than  that  one 
thing  or  another  has  been  neglected  or  overlooked.  A  plate  has  been 
cleaned,  collodionized,  sensitized,  and  exposed  ;  but  the  developer  is 
not  ready ;  or  clean  glasses  are  not  handy;  or  the  intensifier  has  to  be 
made ;  the  plate  dries,  the  film  contracts,  and  the  previous  four  or  five 
operations  go  for  nought. 

Having  a  care  to  see  that  everything  is  in  order,  is  of  the  utmost 
importance  in  portraiture,  for  the  model  as  well  as  the  photographer 
suffers  from  neglect.  The  former  would  have  to  go  again  through  the 
disagreeable  operations  of  posing,  placing  the  head  in  the  head- 
rest, sitting  still,  etc.,  and  this  is,  for  the  public,  little  calculated  to 
form  an  attraction. 

The  first  work  in  making  a  photograph  is  the  cleaning  of  the  glass 
plate. 

1.  THE  CLEANING. 

We  suppose  that  a  number  of  plates,  which  fit  in  the  plate-holder, 
and  have  been  exposed  to  acid,  washed  in  water,  and  dried  with  the 
towel,  as  described  above,  are  at  hand.  Both  sides  should  be  exam- 
ined by  breathing  on  them  ;  the  least  impurity  will  show  itself  by  an 
unequal  adhesion  of  the  breath. 

When  both  surfaces  appear  to  be  equally  clean,  the  one  which  is 
most  smooth  should  be  selected  for  the  reception  of  the  picture.  In 
the  common  glass,  the  two  surfaces  vary ;  the  one  which  has  been  * 
undermost  in  the  oven,  in  flattening  it,  appears  covered  with  number- 
less small  specks,  while  the  other  is  smoother.  One  side  only  requires 
to  be  finely  polished,  as  only  one  side  is  collodionized  ;  but  the  reverse 
side  must  not  become  dirty  either,  as  the  dirt  would  be  transferred  to 
the  silver  bath  and  injure  subsequent  plates. 

The  first  step  in  the  final  cleaning  consists  in  breathing  on  the 
plate  and  rubbing  it  with  a  perfectly  clean  towel,  which  is  used  for  no 
other  purpose  whatever. 

The  polishing  is  done  on  a  perfectly  clean  table,  upon  which  no 
other  substances  than  those  necessary  for  cleaning  are  allowed. 

It  was  formerly  mostly  done  with  alcohol,  old  collodion,  and  the 
like  substances ;  much  simpler,  surer,  and  easier  is  the  cleaning  with 
ammonia  as  proposed  by  the  author.  It  is  said  that  a  mixture  of  1  part 
ammonia  with  1  part  alcohol  is  still  more  efficient.  We  use  only 
watery  ammonia. 


THE  CLEANING. 


115 


The  well-washed  and  dried  plate  is  laid  upon  a  flat  board,  or  in  a 
polishing  frame,  B,  which  is 
adjusted  by  a  screw  to  the 
edge  of  the  plate.  For  a  carte 
de  visite  size,  4  drops  of  strong 
ammonia  are  poured  upon  it, 
and  rubbed  with  a  clean  towel, 
which  has  been  washed  with 
soda  (not  soap),  first,  from  right  to  left,  next,  from  left  to  right,  and 
lastly  up  and  down.  After  this  the  plate  is  rubbed  with  a  clean  dry 
towel.  We  now  breathe  on  the  plate.  When  the  plate  takes  the 
breath  evenly,  and  with  a  blue  color,  everything  is  right. 

Spots  show  themselves  by  the  breath  adhering  unevenly  to  the  plate. 
With  beginners  these  show  themselves  often  at  the  margin  and  in  the 
corners,  because  they  forget  sometimes  to  clean  them.  Whenever 
spots  show  themselves,  we  should  breathe  on  the  spot,  and  polish  with 
a  dry  towel.  If  this  does  not  remedy  it,  we  have  to  repeat  the  polish- 
ing with  ammonia.  Spots  which  do  not  disappear  after  this  treatment 
are  due  generally  to  insufficient  acidulation,  or  dried  spots  of  silver 
solution.  Such  plates  should  be  placed  in  the  acid  again.  There  are 
instances  where  these  spots  do  not  do  any  harm,  but  they  are  rare. 
Polishing  with  leather  is  not  necessary. 

The  cleaning  is  an  operation  which  has  to  be  performed  with  skill, 
judgment,  and  care.  The  beginner  generally  commits  the  error  that 
he  tries  to  clean  with  the  leather  pads  plates  which  have  not  received 
sufficient  care  in  the  acid  bath  and  the  preliminary  washing.  This  is 
time  and  labor  wasted.  Dirty  hands  and  towels,  and  dirty  cleaning- 
rags,  often  cause  much  trouble. 

Cases  where  the  dirty  coat-sleeve  draws  a  line  over  the  cleaned 
plate  occur  every  day.  Many  forget  also  the  careful  cleaning  of  the 
edges  and  corners. 

Very  large  plates  are  cleaned  in  sections.  When  the  plate  has  been 
cleaned  with  the  towel,  the  whole  plate  is  rubbed  over  with  large 
leather  pads  ;  and  when  the  breath  indicates  spots  which  are  not  clean, 
they  are  treated  separately. 

Plates  that  have  been  used  once  before,  and  which  are  coated  with 
varnish,  are  placed  in  a  solution  of  soda.  After  a  few  hours  the  var- 
nish film  is  removed.  They  are  washed  with  water,  next,  with  at  little 
acid,  then  again  with  water,  and  finally  they  are  treated  like  a  new 
plate. 

From  plates  that  have  been  spoiled  only  a  very  short  time  ago,  the 
film  is  easily  removed  by  rubbing  them  over,  and  washing  them  after- 


116 


THE  PRACTICE  OF  PHOTOGRAPHY. 


wards  with  water,  when  they  are  fit  for  use  again.  Plates  on  which 
the  collodion  has  dried  should  be  placed  in  acid.  Old  plates,  which 
have  been  used  over  and  over  again,  become  finally  useless ;  no  clean- 
ing will  restore  them.  Many  plates  are  irreparably  destroyed  by 
scratches — for  instance,  by  carelessly  placing  them  in  the  acid ;  by 
placing  them  flat  on  a  table  (the  latter  should  never  be  done).  The 
remedies  which  are  frequently  recommended  to  facilitate  the  cleaning, 
such  as  tincture  of  iodine,  I  do  not  feel  like  recommending. 

Polished  plates  do  not  keep  longer  than  twenty-four  hours ;  if  kept 
longer  they  attract  so  much  water,  that  repolishing  with  towel  and 
leather  becomes  necessary. 

PRELIMINARY  COATING. 

Instead  of  polishing  plates,  it  has  been  proposed  to  coat  the  same 
with  other  substances,  as  for  instance,  albumen,  collodion,  caoutchouc, 
etc.  Coatings  of  this  kind  will  form  a  clean  surface  even  on  a  plate 
which  is  otherwise  only  polished  with  great  difficulty,  and  they  keep 
longer  than  a  polished  plate.    We  have  tried  the  following  film  : 

A.  Collodion. — Dissolve  1^-  parts  collodion  in  30  parts  of  alcohol  and 
70  parts  of  ether.  After  it  has  settled,  the  washed  and  dried  plates  are 
coated  with  it,  and  put  away  to  dry. 

This  coating  is  sometimes  dissolved  when  the  iodized  collodion  is 
poured  over  it. 

b.  Caoutchouc  Solution. — 1  gramme  caoutchouc  is  dissolved  in  100 
grammes  of  chloroform.  This  solution  is  effected  in  three  to  four  days, 
the  clear  part  is  poured  off,  and  diluted  with  nine  times  its  volume  of 
light  petroleum  benzine,  and  filtered  twice.  With  this  solution  plates 
are  coated  the  same  as  with  collodion,  after  they  have  been  washed, 
dried,  and  dusted.  The  excess  of  liquid  which  is  poured  off  the  plate 
is  collected  in  a  separate  bottle,  and  after  being  filtered  it  can  be  used 
again.    In  a  damp  climate  this  coating  is  preferable  to  albumen. 

c.  Coating  with  Albumen. — This  has  been  employed  mostly  in 
America,  and  generally  with  good  results.  The  white  of  a  fresh  egg 
and  two  drops  of  carbolic  acid  are  placed  in  a  bottle  with  clean  splint- 
ers of  glass,  and  shaken  for  half  an  hour ;  the  clear  part  is  decanted 
from  the  froth,  and  diluted  with  its  volume  of  ammonia.  The  concen- 
trated solution  will  keep  for  six  months.  Before  using  it  a  portion  is 
filtered,  diluted  with  twice  its  volume  of  water,  and  filtered  twice  more. 
The  glass  plates  are  acidulated,  well  washed,  and  placed  into  a  dish 
with  clean  water.  If  we  wish  to  albumenize  them,  we  pour  a  little 
distilled  water  over  the  plate  to  remove  the  wash  water;  afterwards  a 


THE  COLLODTONIZING. 


117 


few  cubic  centimetres  of  albumen  solution  are  poured  over  the  plate 
to  remove  the  distilled  water,  and  after  draining  the  plate,  the  final 
solution  is  poured  over  it.  The  excess  which  drains  off  after  coating 
is  not  collected.  The  plates  are  placed  on  a  clean  rack,  and  left  to 
dry  in  a  place  perfectly  free  from  dust. 

In  a  dry  climate  they  keep  for  months;  per  T\y  square  metre  =  1 
square  foot,  about  20  cubic  centimetres  of  albumen  solution  are  neces- 
sary. Albumenized  plates  have  the  advantage  that  the  collodion 
adheres  to  them  very  firmly,  while  from  polished  plates  it  is  frequently 
removed  in  washing.  To  find  which  of  the  two  sides  of  the  plate  has 
been  albumenized,  it  is  only  necessary  to  breathe  on  the  plate ;  the 
breath  adheres  readily  to  the  glass,  while  the  albumen  film  assumes 
rainbow  colors. 

Anderson  proposes  to  add,  in  place  of  ammonia,  glacial  acetic  acid. 

2.  THE  DUSTING. 

When  a  plate  has  been  rubbed  with  the  leather  pads  it  generally 
becomes  electrical,  and  attracts  dust  and  fibres,  which,  if  left  on  the 
plate,  would  spoil  both  collodion  and  nitrate  bath.  The  plate  is  left 
on  the  drying-rack  for  a  few  minutes ;  it  loses  its  electricity ;  it  is  now 
dusted  off  very  carefully  with  a  camel's  hair  brush  (the  duster). 

It  is  best  to  hold  the  plate  by  one  corner,  in  the  left  hand,  in  a  ver- 
tical position. 

The  duster  should  not  be  laid  on  the  table,  but  hung  against  the  wall. 
The  dusting  should  be  done  in  the  room  next  to  the  dark-room. 

3.  THE  COLLODIONIZING. 

The  covering  of  a  plate  with  an  even  film  of  collodion  requires  some 
practice.  The  beginner  should  try  his  skill  on  worthless  plates  with 
old  and  useless  collodion. 

The  glass  plate  (Fig.  60)  should  be  held  with  the  right  hand  per- 
fectly horizontal  by  the  upper  left  corner  (a)  ;  a  pool  of  collodion  is 
poured  on  the  centre  of  the  plate  ;  when  a  sufficient  quantity  has  been 
poured  on,  the  plate  is  gently  inclined,  that  the  collodion  may  first 
flow  to  the  corner  b,  next  to  a,  then  to  c,  and  finally  to  d.  The  plate 
is  now  inclined  gently,  by  moving  it  in  its  plane  around  d.  Under  d 
the  neck  of  the  collodion  bottle  is  placed  to  receive  the  excess  of  the 
fluid.  The  plate  is  now  gradually,  and  while  moving  it  constantly 
with  a  rocking  motion,  returned  to  the  vertical  position.  The  collo- 
dion evaporates  while  draining  from  the  plate,  and  unless  the  latter 
be  moved  to  and  fro,  it  will  dry  in  streaks  (diagonal)  in  the  direction 


118 


THE  PRACTICE  OF  PHOTOGRAPHY. 


of  the  drainage.  The  motion  should  always  be  in  the  plane  of  the 
plate. 

It  is  also  important  that  the  collodion  does  not  collect  on  the  back 
of  the  plate;  by  evaporation  it  causes  unequal  drying  of  the  film, 
and  besides  imparts  impurities  to  the  bath  by  pieces  of  collodion 
becoming  detached  and  floating  in  the  bath.  The  collodion  should 
not  touch  the  fingers  holding  the  plate,  as  it  will  dissolve  fat  from  the 
skin,  which  may  cause  dark  streaks  in  the  picture. 

The  plate  should  be  kept  in  constant  motion,  and  the  collodion  bottle 
should  be  closed  again  at  once,  a  circumstance  which  is  always  neglected 
by  beginners. 


Fig.  60. 


o  d 

To  operators  who  desire  to  work  very  clean,  we  would  recommend 
to  collect  the  collodion  which  drains  from  a  plate  into  a  separate 
bottle ;  this  prevents  impurities  from  getting  into  the  supply-bottle, 
such  as  dust  from  the  plates,  etc. 

When  the  collodion  becomes  thicker,  and  the  last  drop  has  ceased 
to  fall,  care  becomes  necessary.  When  the  lower  corner  has  dried  so 
far  that  the  collodion  will  tear,  then  the  moment  has  arrived  for 
placing  the  plate  into  the  silver  bath.  When  the  plate  is  dipped  too 
soon,  the  film  will  become  weak  and  peel  off  in  washing.  When  it  is 
dipped  too  late,  the  upper  parts,  which  have  become  too  dry,  will 
either  not  become  sensitive  at  all,  or  only  superficially,  and  a  dry 
border  will  be  formed,  which  will  show  itself  after  silvering.  It 
shows  of  course  on  the  upper  margins  of  the  plate  where  the  film  is 
thinnest. 

It  is  also  important  that  the  back  of  the  plate  be  kept  free  from  col- 


THE  SENSITIZING.  119 

lodion,  as  it  causes  by  evaporation,  and  consequent  cooling,  unequal 
drying  of  the  film.  It  also  contaminates  the  nitrate  bath  by  the  peel- 
ing off  of  particles  of  the  collodion. 

As  the  handling  of  the  plate  with  the  fingers  has  its  disadvan- 
tages, pneumatic  plate-holders  have  been  invented,  consisting  of  small 
bags  of  rubber,  which,  when  the  air  is  pressed  out  of  them,  hold  the 
plate.  They  often  fail,  and  in  hot  weather  the  film  over  the  holder 
dries  slower,  and  the  picture  on  this  spot  becomes  thinner. 

The  coating  of  larger  plates  is  somewhat  more  difficult.  They  can- 
not be  held  in  the  hand ;  they  have  to  be  supported  in  the  centre.  A 
corked  bottle  answers  very  well  for  this  purpose. 

We  do  not  recommend  the  pneumatic  holders  ;  they  very  often  fail, 
and  the  loss  of  a  plate  is  the  result. 

Large  plates  are  silvered  also  by  placing  them  on  a  towel;  the  towel 
is  formed  into  a  ball ;  the  plate  is  placed  on  it,  and  the  collodion  is 
poured  on  the  plate  ;  it  requires  some  nice  balancing  to  coat  the  whole 
plate  evenly,  and  the  beginner  is  likely  to  spoil  a  few  plates  before  he 
becomes  an  expert ;  but  it  enables  the  operator  to  coat  the  whole  plate 
without  leaving  out  a  corner,  and  for  large-sized  plates  it  is  to  be  rec- 
ommended. 

It  would  not  do  to  place  the  plate  on  the  hand ;  the  warmth  of  the 
hand  would  cause  a  more  rapid  evaporation  of  the  col- 
lodion, and  dry  spots,  where  the  fingers  had  supported        FrG-  61- 


the  plates,  would  be  the  result. 

Collodion  bottles,  constructed  especially  for  pouring 
collodion,  have  been  made,  and  in  America  they  are 
known  as  the  "  Cometless "  Collodion  Bottle.  The 
mouth  is  covered  by  a  large  cap,  k,  to  exclude  dust, 


and  the  excess  of  collodion  is  collected  in  the  funnel, 
b,  from  whence  it  flows  through  a  side  opening  back  into  the  bot- 
tle, a.    They  are  very  good. 

4.  THE  SENSITIZING. 

Before  we  commence  coating  a  plate,  we  must  have  the  silver  bath 
ready  and  in  good  condition;  for,  we  have  stated  above,  that  the  plate 
must  be  dipped  at  the  moment  it  has  reached  a  sufficient  degree  of 
dryness.  Loss  of  time  makes  the  result  doubtful.  The  purpose  01 
placing  the  coated  plate  into  the  bath  is  to  transform  the  salts  ot 
iodine  and  bromine  into  iodide  and  bromide  of  silver.  Although  this 
process  of  decomposition  is  a  very  simple  one,  still  there  are  some  me- 
chanical difficulties  which  sometimes  prevent  the  production  of  a  per- 
fectly homogeneous  film  of  these  salts. 


120 


THE  PRACTICE  OP  PHOTOGRAPHY. 


The  collodion  film  is  alcoholic ;  the  bath  is  watery.  Both  repel 
each  other  at  first,  as  grease  and  water  would  do,  and  this  is  the  dif- 
ficulty in  getting  the  bath  to  flow  perfectly  even  over  the  plate. 
Where  the  flow  of  the  bath  has  been  checked  for  a  moment,  streaks 
are  the  results.  Several  methods  have  been  suggested  to  avoid  this. 
We  will  describe  at  first, 

a.  THE  SENSITIZING  IN  THE  BATH. 

The  bath  is  a  narrow  glass  trough  corresponding  in  its  shape  with 
the  form  of  the  plate  a  (Fig.  62).  The  filtered  silver  solution  is 
poured  into  it.  The  bath  is  generally  placed  into  a  wooden  box  of 
convenient  form,  and  fixed  in  an  inclined  position.  The  box,  K,  is 
provided  with  a  lid  having  a  slit,  B,  in  it.  The  sides  of  the  bath, 
front  and  back,  must  be  curved  to  prevent  the  tender  collodion  film 
from  touching  them. 

Porcelain  baths  are  inferior  to  glass;  their  opacity  prevents  us  from 
examining  the  sides  and  the  fluid  to  see  whether  everything  is  per- 
fectly clean,  not  to  mention  the  occasional  peeling  off  of  the  glazing. 

Fig.  62. 


h 


India-rubber  baths,' on  account  of  the  resinous  organic  matter  con- 
tained in  them,  will  in  course  of  time  affect  the  bath  injuriously. 

For  lowering  the  plate  into  the  bath  an  instrument,  made  either  of 
glass  or  silver  wire,  called  a  dipper,  is  used ;  the  lower  end  is  bent  so 
as  to  form  a  hook  on  which  the  plate  rests.  Glass  dippers  are  easily 
broken.    The  best  are  those  made  of  silver  wire. 


SENSITIZING  IN  DISHES. 


121 


Gutta  percha  dippers  are  objectionable  for  the  reasons  mentioned 
above,  when  speaking  of  India-rubber  baths. 

Whoever  wishes  to  use  India-rubber  goods  (they  are  advantageous 
for  travelling  photographers,  as  they  are  not  liable  to  breakage), 
should  take  care  that  the  solution  does  not  remain  longer  in  contact 
with  them  than  is  absolutely  necessary ;  they  should  also  be  washed 
very  frequently. 

For  the  purpose  of  sensitizing,  the  plate  is  placed  on  the  dipper, 
the  corner  by  which  the  plate  has  been  held  (see  Fig.  60)  being  down- 
ward; the  plate  is  lowered  into  the  bath  with  a  steady  motion.  Any 
interruption  in  this  steady  movement  will  produce  lines,  which  cross 
the  plate  horizontally,  and  become  visible  after  development. 

The  alcoholic  collodion  film  repels  at  first  the  watery  bath,  and  the 
latter  runs  off  the  plate  in  greasy  lines  when  it  is  removed  from  the 
bath  shortly  after  immersion. 

The  plate  is  moved  up  and  down  in  the  bath  until  the  greasy  lines 
disappear ;  when  this  has  taken  place,  and  not  before,  the  plate  is 
ready  for  exposure.  With  a  concentrated  bath,  and  in  warm  weather, 
the  sensitizing  progresses  very  rapidly;  with  a  low  temperature  and  a 
weak  bath,  the  process  is  slow.  A  plate  which  has  been  exposed  too 
soon  will  show,  in  the  place  of  the  greasy  spots  and  lines,  black  spots 
and  lines,  when  the  developer  is  poured  on. 

The  plate,  when  it  is  removed  from  the  bath,  is  placed  in  the  same 
position  on  pieces  of  clean  blotting-paper,  the  top  of  the  plate  resting 
against  the  wall.  In  the  intervening  time,  while  the  plate  is  draining, 
we  place  into  the  lower  corners  of  the  plate-holder  small  pieces  of  clean 
blotting-paper,  not  omitting,  however,  to  wipe  the  corners  first  very 
carefully ;  and,  finally,  we  place  the  plate  into  the  plate-holder,  taking 
care  that  the  four  corners  are  in  their  proper  places,  and  that  the 
corner  which  left  the  bath  last  occupies  also  the  lower  corner  in  the 
plate-holder. 

All  these  operations  must  be  performed  in  the  dark-room  with  a  non- 
actinic  light ;  bringing  the  plate  too  close  to  a  bright  gaslight  should  also 
be  avoided. 

The  greatest  cleanliness  of  the  hands  and  all  and  every  object  which 
comes  in  contact  with  the  plate  is  absolutely  necessary. 

The  sensitizing  should  be  done  on  a  table  from  which,  excepting 
collodion,  all  the  other  chemicals  are  excluded,  particularly  hyposul- 
phate  of  soda. 

b.  SENSITIZING  IN  DISHES. 

This  has  the  advantage  that  a  very  small  quantity  of  silver  bath  will 
be  sufficient ;  on  the  other  hand,  there  is  the  disadvantage,  that  the 


122 


THE  PRACTICE  OF  PHOTOGRAPHY. 


scum  has  to  be  removed  from  the  bath  before  every  immersion  of  a 
plate ;  after  it  has  been  used  it  has  to  be  poured  into  a  bottle,  while  in 
the  upright  bath  the  solution  can  be  kept. 

The  sensitizing  in  dishes  is  more  suitable  for  amateurs  and  small 
establishments ;  for  large  ateliers  it  is  unpractical. 

The  dishes  are  made  of  the  same  material  as  the  baths, — glass,  por- 
celain, and  gutta  percha.  We  prefer  the  glass  dishes  (see  a,  Fig.  63) 
for  the  negative  process. 

The  genuine  square  Japanese  dishes,  with  rounded  sides  and  cor- 
ners, are  excellent  (see  Fig.  64).  They  are  light,  do  not  break  easily, 
and  resist  the  influence  of  the  chemicals  very  well.  Before  using,  a 
solution  of  permanganate  of  potash  should  be  placed  in  them  for 
twelve  hours. 

The  bath  solution  is  filtered  into  the  dish  until  it  covers  the  bottom 
about  one-quarter  of  an  inch  deep;  the  scum  is  removed  by  draw- 
ing strips  of  writing-paper  over  the  surface  until  they  appear  to  be 
free  from  dirt;  the  coated  plate  is  now  placed  vertically  in  the  dish,  the 
corner  by  which  it  has  been  held  in  coating  being  downward ;  the  front 
of  the  plate  touches  the  side  of  the  dish.  The  plate  is  now  lowered, 
with  a  very  steady  motion,  until  it  becomes  entirely  submerged,  the 
coated  side  being  downward. 

The  upper  margin  of  the  plate  is  seized  with  a  hook  of  silver  or 
bone  (Fig.  63,  a),  and  moved  repeatedly  up  and  down  until,  when 

£3 


viewed  in  reflected  yellow  light,  the  greasy  lines  have  all  disappeared  ; 
the  plate  is  finally  removed  from  the  dish  in  a  vertical  position  and 
placed  on  strips  of  blotting-paper  to  drain  off  the  superfluous  solution. 

When  the  quantity  of  fluid  in  the  dish  is  too  small,  the  solution  is  re- 
pulsed, and  air-bubbles  will  collect  on  the  plate  and  cause  round  spots 
when  the  developer  is  poured  on. 

If  the  amount  of  bath  solution  is  small,  the  dish  S,  after  the  plate 
has  been  placed  into  it,  should  be  tilted  up  with  the  left  hand,  as 
shown  in  Fig.  64.  With  the  right  finger  the  plate  is  lowered  until  it 
nearly  touches  the  fluid,  after  this  the  right  hand,  and  next  the  left 
hand  is  removed.  In  this  way  the  bath  will  flow  over  the  plate  with 
one  bound.  The  dish  should  afterwards  be  moved  smartly  so  as  to 
obviate  any  repulsion.    The  more  energetically  the  dish  is  moved, 


Fig.  63. 


SENSITIZING  IN  DISHES. 


123 


the  more  rapidly  will  the  streaks  disappear.  In  summer-time  sooner, 
in  winter  later. 

For  this  manipulation  a  plentiful  supply  of  bath  solution  is  there- 
fore necessary.  The  plate  is  placed  vertically  in  the  dish  as  described 
above,  but  at  the  same  time  the  dish  is  moved  in  order  to  hasten  the 
flow  of  the  liquid  over  the  plate ;  when  this  is  neglected  we  get  very 
often  a  plate  covered  with  curved  sensitizing  lines. 

With  this  method  the  plate  becomes  sensitized  very  rapidly,  as  the 
alcohol  can  readily  rise  to  the  surface.  The  dish  is  moved  until  the 
greasy  lines  have  all  disappeared ;  the  plate  is  lifted  out  with  a  rapid 
motion,  so  as  to  wash  off  small  floating  particles  (pieces  of  collodion 
film,  etc.).    Otherwise  we  proceed  as  has  been  described  above. 

This  method  requires  more  practice,  but  in  the  hands  of  a  skilful 
operator  it  gives  the  cleanest  plates.  For  large  plates  this  method  is 
generally  employed. 

To  facilitate  the  immersion,  half-covered  dishes  have  been  con- 
structed (Fig.  63,  left  figure) ;  when  such  a  dish  is  placed  in  a  verti- 
cal position,  the  solution  collects  in  the  covered  part,  and  by  rapidly 


Fig.  64. 


lowering  it,  the  whole  plate  will  be  quickly  overflowed.  It  should  be 
so  arranged  that  the  wave  of  the  bath  flows  first  over  the  thickest 
part  of  the  plate  containing  the  most  alcohol,  because  here  the  repel- 
ling action  is  the  strongest. 

In  regard  to  draining,  etc.,  proceed  as  directed  above. 

The  bath  which  is  kept  in  dishes  should  alw7ays  be  carefully 
skimmed  previous  to  preparing  a  plate;  the  dish  should  be  kept  care- 
fully covered. 


124 


THE  PRACTICE  OF  PHOTOGRAPHY. 


The  best  temperature  for  a  bath  is  66°  Fahr.  In  hot  summer 
weather,  the  bath  is  improved  by  placing  it  in  a  tub  of  cold  water. 

5.  THE  EXPOSURE. 

Before  placing  the  plate-holder  with  the  plate  into  the  camera,  we 
should  cast  a  glance  over  the  object  to  be  taken,  and  also  on  the 
ground-glass,  to  see  if  everything  is  in  order.  The  ground-glass  is 
next  replaced  by  the  plate-holder,  taking  great  care  that  the  appa- 
ratus does  not  change  its  position  in  the  least.  With  equal  care  must 
the  shutter  of  the  plate-holder  be  drawn,  and  particularly  for  long 
exposures  it  is  advisable  to  throw  a  black  cloth  over  the  shutter  and 
plate-holder ;  when  this  has  been  done,  the  cap  is  removed  from  the 
lens  as  gently  as  possible  so  as  to  avoid  moving  the  instrument. 

How  long  shall  I  expose  ?  is  the  question  which  we  hear  from  every 
beginuer,  and  sometimes  the  experienced  operator  is  doubtful  on  this 
point. 

The  time  of  exposure  depends  on  the  chemical  intensity  of  the  light, 
the  brightness  of  the  object  to  be  taken,  the  amount  of  light  which  the  lens 
has,  and  on  the  size  of  the  stops  employed. 

Many  circumstances  have  to  be  taken  into  account  at  the  same 
time  ;  experience  is  the  only  guide  ;  the  only  criterion  which  the  pho- 
tographer can  employ  is  the  examination  of  the  picture  on  the  ground- 
glass.  According  to  its  appearance  after  the  picture  has  been  sharply 
focussed  and  the  proper  stop  inserted,  according  to  the  brightness 
which  it  shows  on  the  ground-glass  must  he  regulate  the  time  of  ex- 
posure. 

For  portrait  and  landscape  photographers,  it  may  here  not  be  out 
of  place  to  call  attention  to  the  enormous  differences  in  the  intensity 
of  light  in  the  different  seasons.  With  a  clear  sky  the  light  is  at  12 
o'clock,  noon,  on  the  21st  of  December  of  the  same  intensity  as  at  6J 
o'clock  in  the  evening  on  the  21st  of  June.  Similar  differences  exist 
for  all  seasons.  The  study  of  the  chemical  meteorology  is  by  no  means 
of  secondary  interest. 

During  exposure  due  care  should  be  taken  that  the  apparatus  is 
not  shaken ;  moving  to  and  fro  must  be  avoided ;  the  objective  should 
be  protected  against  extraneous  light. 

A  box  surrounding  the  objective  or  fastened  to  the  stand  will  ac- 
complish this. 

This  precaution  is  particularly  necessary  when  the  atelier  is  exposed 
to  direct  sunlight,  or  when  we  work  with  much  top-light.  In  hand- 
ling the  plate-holder  the  vertical  position  should  be  maintained  as 
much  as  possible. 


TIIE  DEVELOPMENT. 


125 


It  must  be  remembered  that  the  plate  is  placed  wet  into  the  plate- 
holder  ;  that  the  solution  will  collect  on  the  lower  margin  ;  and  when 
we  reverse  the  position,  the  solution  which  has  collected  at  the  bottom 
will  run  back  over  the  plate  and  generally  produce  stains. 

The  principal  thing  is  to  operate  rapidly.  The  plate,  particularly 
in  warm,  dry  weather,  will  only  keep  moist  for  a  short  time  ;  it  is 
therefore  necessary  that  every  preparation  should  be  taken  beforehand, 
so  that  the  plate  may  pass  through  the  different  stages  rapidly  and 
without  any  delay. 

6.  THE  DEVELOPMENT. 

The  exposed  plate  is  carried  into  the  dark-room  and  placed  in  its 
original  vertical  position.  Having  satisfied  ourselves  that  the  devel- 
oper, intensifier,  fixing-bath,  and  clean  glasses  are  all  in  their  proper 
position,  and  the  light  in  the  dark-room'  being  not  too  strong,  the 
plate  is  carefully  removed  from  the  plate-holder,  seizing  it  in  such  a 
manner  that  it  is  inclined  towards  the  corner  which  was  lowest  in  the 
plate-holder.  This  is  done  in  the  best  way  by  opening  the  back  of 
the  plate-holder  (D,  Fig.  24),  which  is  lying  on  the  table ;  the  plate- 
holder  is  then  seized  in  such  a  manner  that  the  thumb  holds  the  lid 
and  prevents  its  falling  back,  the  plate-holder  is  then  reversed,  and 
the  plate  falls  on  the  flat  right  hand.  The  plate-holder  is  now  put 
aside  (in  order  to  be  cleaned  presently),  and  with  the  first  three 
fingers  of  the  left  hand,  the  plate  is  seized  by  the  corner  which 
was  lowest  in  the  plate-holder  and  as  shown  in  Fig.  60  (the  same 
corner  which  was  held  in  the  hand  while  the  plate  was  coated  with 
collodion),  in  such  a  manner  that  the  side  a,  e,  is  directed  horizontally 
against  the  chest,  and  a  little  lower  than  the  side  b,  d.  Along  this 
higher  side  b,  d,  the  developer  is  poured.  It  will  easily  be  observed 
that  at  the  lower  margin  the  surplus  liquid  has  collected.  This  liquid 
must  not  run  back  over  the  plate,  as  it  may  cause  streaks  and  stains, 
as  has  been  explained  above.  The  developer  is  therefore  poured  on 
the  upper  corner,  with  an  even  sweep,  that  it  may  cover  at  once  the 
whole  plate ;  a  part  will  run  off  on  the  opposite  corner  and  take  with 
it  the  silver  solution  which  may  still  adhere  to  it. 

For  the  beginner  it  will  be  difficult  to  pour  the  developer  evenly 
over  the  whole  plate,  as  the  watery  developing  solution  is  repelled  by 
the  alcoholic  collodion  film,  and  in  the  places  where  the  flow  of  the 
wave  has  been  arrested,  lines  will  show  themselves — the  so-called 
developing  lines — which  no  subsequent  flowing  with  the  developer 
will  remove. 

Neither  must  the  developer  be  dashed  on  to  the  plate  too  energeti- 
cally, as  that  generally  produces  a  bright  spot.    By  pouring  the  de- 


126 


THE  PRACTICE  OP  PHOTOGRAPHY. 


veloper  on  too  rapidly,  the  silver  solution  is  removed  from  the  place 
where  the  developer  strikes  the  plateuand  the  picture-forming  mate- 
rial is  reduced  in  quantity ;  the  pouring  of  the  developer  must  be 
practiced  before  perfect  results  can  be  expected. 

It  is  further  to  be  observed,  that  the  upper  margin,  upon  which  the 
developer  is  poured,  must  be  coated  with  a  film  sufficiently  strong  to 
resist  the  shock ;  for  this  purpose  I  recommend  placing  the  thickest 
part  of  the  film  (the  part  from  which  the  collodion  has  been  drained 
back  into  the  bottle)  uppermost  into  the  plate-holder,  and  by  follow- 
ing the  above  directions  it  will  come  in  the  proper  position  in  the  de- 
velopment. 

When  the  developer  covers  the  plate,  the  picture  becomes  visible. 
When  this  takes  place  too  rapidly,  then  the  plate  has  been  overex- 
posed ;  when  it  takes  place  very  slowly,  the  plate  is  underexposed. 
With  a  normal  development  the  high  lights  appear  first;  in  a  portrait, 
for  instance,  the  white  linen  (shirt-bosom),  etc.,  next  the  face  and 
hands  appear,  then  the  light  vest  or  pants,  the  furniture  and  draperies, 
and  finally  the  dark  coat.  The  appearance  of  the  picture  should  be 
watched  with  the  greatest  care ;  the  developer  should  be  moved  in 
every  direction,  and  fresh  solution  should  be  added  when  necessary. 
The  dark  shadows  must  be  watched  (particularly  the  folds  in  a 
dark  coat  in  a  portrait,  or  the  foliage  in  a  landscape)  to  see  if  all 
the  details  come  out  properly.  It  is  of  course  necessary  to  be  per- 
fectly familiar  with  the  original  in  order  to  .  judge  correctly.  When 
in  spite  of  long-continued  development,  the  details  in  the  shadows  do 
not  appear,  then  the  plate  has  been  underexposed,  and  no  subsequent 
operation  will  remedy  this  defect. 

An  overexposed  plate  will  show  all  the  details  in  the  shadows,  but 
the  contrasts  which  constitute  the  beauty  of  a  picture  are  wanting. 
The  plate  is  monotonous  and  yields  similar  prints. 

The  transitions  from  light  to  shade  are,  in  an  underexposed  plate, 
generally  too  abrupt,  or,  as  the  photographers  call  it,  they  are  hard. 

Long  experience  is  the  only  thing  which  will  enable  us  to  decide 
from  the  film  with  certainty,  certainly  when  a  plate'  has  received  the 
proper  exposure. 

When  the  plate  has  been  fully  developed,  the  developer  is  washed 
off,  the  back  of  the  plate  is  washed  with  the  hand,  and  the  plate  is 
examined  carefully  by  transmitted  light.  When  the  plate  is  faulty, 
no  further  operation  is  necessary ;  the  plate  is  simply  cleaned  and  put 
aside.  When,  however,  it  appears  clear  and  transparent  in  the 
shadows,  with  sufficient  detail  in  the  dark  parts,  soft  in  the  half-tones, 
sharp,  and  free  from  spots,  then  it  should  be  intensified. 


THE  INTENSIFICATION. 


127 


7.  THE  INTENSIFICATION. 

This  is  generally  done  with  a  solution  of  pyrogallic  acid ;  the  expe- 
rienced operator  will  succeed,  however,  with  the  ordinary  iron  devel- 
oper. 

With  a  brilliant,  intense  light,  some  collodions  will  give  pictures 
which  do  not  require  any  strengthening ;  but  in  many  cases  we  cannot 
well  do  without  it. 

A  small  quantity  of  the  watery  pyrogallic  solution  is  poured  into  a 
clean  glass,  and  an  equal  quantity  of  a  solution  of  nitrate  of  silver  is 
added;  the  mixture  is  at  once  poured  upon  the  plate ;  by  moving  it  to 
and  fro  the  liquid  will  spread  over  the  whole  plate,  leaving  no  spot 
uncovered;  after  a  little  while  the  intensifier  is  poured  back  into  the 
glass,  while  at  the  same  time  the  plate  is  examined  by  transmitted 
light.  The  spots  on  the  back  of  the  plate,  which  are  easily  removed 
with  the  finger,  must  not  mislead  us. 

When  the  plate  has  reached  the  necessary  density  (the  determina- 
tion of  which  is  purely  a  matter  of  experience),  the  intensifier  must  be 
washed  off  at  once ;  if  the  plate  has  not  reached  the  necessary  density, 
the  intensifier  is  poured  on  again,  provided  that  the  liquid  is  still  clear  ; 
a  brownish  tint  does  not  hurt. 

If  it  has  become  turbid,  it  must  be  rejected,  and  a  fresh  solution  of 
pyrogallic  acid  and  silver  is  poured  on. 

Sometimes  a  bluish  precipitate  will  form  in  the  shadows  ;  when  this 
takes  place  it  is  an  indication  that  the  intensifier  is  not  sufficiently 
acid,  and  more  of  the  latter  must  be  added. 

When  the  plate  has  reached  sufficient  density,  and  has  been  washed 
thoroughly,  it  is  ready  for  fixing. 

When  we  intensify  with  iron  solution,  equal  to  twice  as  much  ni- 
trate of  silver  solution  should  be  mixed  with  the  iron,  and  poured  upon 
the  plate,  after  development,  without  previous  washing. 

The  intensification  progresses  as  rapidly  and  comfortably  as  with 
the  pyrogallic  acid  solution.  Sometimes,  however,  the  intensifier  does 
not  mix  readily  with  the  developer  which  may  still  remain  on  the 
plate ;  the  liquid  containing  the  most  alcohol  will  repel  the  one  con- 
taining the  least ;  this  must  be  remedied  by  giving  an  equal  quantity 
of  alcohol  to  both.    When  this  is  neglected,  spots  are  likely  to  result. 

With  landscapes  and  portraits  intensifying  is  comparatively  an  easy 
work.  With  reproductions,  however,  as  for  instance  copies  of  draw- 
ings, it  requires  more  time  and  great  care.  The  fine  lines  become 
easily  veiled,  or  the  plate  is  unequal,  when  the  intensifier  has  not  cov- 
ered the  whole  plate  equally. 


128 


THE  PRACTICE  OF  PHOTOGRAPHY. 


The  place  on  which  the  iutensifier  is  poured  becomes  first  generally 
a  little  darker,  a  circumstance  which  in  portraiture  can  be  turned  to 
advantage  by  pouring  the  liquid  on  the  head,  and  thus  giving  to  it 
additional  density. 

The  beginner  should  remember  that  the  intensifier  maizes  the  plate  only 
denser  and  richer  in  co?itrast,  but  does  not  add  to  the  details.  It  is, 
hence,  useless  to  try  to  improve  an  underexposed  plate  by  intensify- 
ing it. 

Concerning  intensification,  after  fixing,  we  will  speak  further  on. 

8.  THE  FIXING. 

When  the  intensified  plate  has  been  washed  (sufficiently  to  remove 
the  remnant  of  silver  solution),  and  when  the  back  has  been  rubbed 
clean,  a  solution  of  hypo  or  cyanide  is  poured  on,  as  before  explained. 

Either  solution  dissolves  the  iodide  and  bromide  of  silver  out  of  the 
film  by  forming  double  salts. 

The  cyanide  of  potassium  affects  the  plate  a  little,  because  it  dis-" 
solves  in  the  presence  of  oxygen  the  gray  silver  forming  the  outlines 
of  the  picture. 

This  is  of  advantage  for  plates  where  the  intensification  has  been 
carried  too  far,  but  for  thin  negatives  it  is  a  disadvantage.  In  the 
latter  case  close  watching  is  necessary,  and  when  the  last  trace  of 
iodide  of  silver  has  disappeared,  the  plate  should  be  washed  at  once 
with  water. 

Hyposulphite  of  soda  does  not  affect  the  plates,  but  its  action  is 
slower  than  that  of  cyanide  of  potassium.  When  the  solution  is  old 
or  very  diluted,  in  flowing  it  unevenly  over  the  plate,  it  is  apt  to  form 
black  lines,  the  so-called  fixing  lines. 

It  is  necessary  to  wash  the  fixed  plates  thoroughly  in  water  to  re- 
move the  soda,  or  it  will  afterwards  decompose  in  the  picture  and 
cause  its  destruction. 

Plates  which  have  been  fixed  with  cyanide  of  potassium  are  easier 
washed.  The  proper  point  is  ascertained  .by  placing  a  drop  of  the 
water,  dripping  from  the  plate,  on  the  back  of  the  hand  and  tasting 
it.  The  smallest  quantity  of  cyanide  will  indicate  itself  by  imparting 
to  the  water  a  bitter  taste. 

(Poisoning  is  not  to  be  feared  unless  a  person  is  exceedingly  care- 
less; but  the  liquid  should  not  be  tasted  until  the  plate  has  been 
washed  for  some  time.  Be  very  careful.)  After  fixing,  the  washed 
plate  is  placed  on  clean  blotting-paper  to  dry. 


THE  VARNISHING. 


129 


9.  THE  INTENSIFYING  AFTER  FIXING. 

It  has  frequently  been  recommended  to  postpone  the  intensification 
until  after  the  plate  has  been  fixed.  When  we  attempt  this  in  the 
ordinary  manner,  with  silver  salt,  we  will  always  find  that,  unless  it 
has  been  washed  very  carefully  after  fixing,  the  plate  is  apt  to  become 
spotted. 

This  circumstance  makes  this  mode  of  intensification  objectionable. 

For  intensification  after  fixing,  a  number  of  peculiar  metal  salts  have 
been  proposed,  which,  with  the  metallic  silver  of  the  picture,  cause 
peculiar  decompositions,  and  form  pictures  of  different  composition, 
which  offer  greater  resistance  to  the  passage  of  chemical  rays.  The 
chloride  of  mercury  we  mention  particularly,  also  a  solution  of  iodide 
of  mercury  in  iodide  of  potassium,  also  a  mixture  of  red  permanganate 
of  potassium  and  the  oxide  of  uranium.  These  methods  may  be  of 
advantage  for  special  purposes,  as,  for  instance,  the  production  of 
negatives  for  the  photo-lithographic  process.  For  the  ordinary  pho- 
tographer, however,  the  silver  intensifier  is  preferable,  the  more  so  as 
the  permanence  of  the  plate  produced  by  the  other  methods  has  not 
been  established  as  yet. 

Of  particular  importance,  however,  are  these  changes  in  the  chemi- 
cal composition  of  the  film  for  the  email  or  enamel  process. 

c       10.  THE  VARNISHING. 

The  delicate  picture  on  the  collodion  film  would  soon  be  ruined  by 
mechanical  injuries  (scratches,  etc.),  if  we  did  not  provide  it  with  a 
covering  offering  more  resistance. 

Such  a  covering  is  the  varnish.  The  loose  particles  of  the  film  on 
the  margins  of  the  plate  are  first  removed  ;  the  plate  is  warmed  over 
a  lamp,  and  the  varnish  is  poured  on  exactly  as  the  collodion  is  poured 
on  in  coating  a  plate;  the  excess  of  varnish  is  poured  back  into  the 
bottle,  and  the  plate  is  placed  on  paper  and  left  to  dry.  The  back  of 
the  plate  should  be  kept  clear  from  varnish,  as  it  will  produce  unequal 
drying  of  the  film. 

If  the  plates  are  too  hot,  when  the  varnish  is  poured  on,  the  plate 
is  apt  to  become  streaked ;  if  too  cold,  the  film  will  appear  dull  and 
less  transparent. 

Sometimes  the  varnish  will  eat  away  parts  of  the  film ;  this  takes 
place  when  it  contains  too  strong  an  alcohol  or  turpentine,  which  dis- 
solves the  collodion  film.    One  per  cent,  of  water  added  to  it  and 

9 


130 


THE  PRACTICE  OF  PHOTOGRAPHY. 


warming  till  the  precipitate  caused  by  the  water  is  redissolved,  will 
remedy  this. 

Beginners  generally  make  mistakes  in  varnishing.  Glad  to  have 
finished  a  plate  so  far,  they  become  careless  in  this  last  finishing  ope- 
ration, and  spoil  many  a  plate  in  varnishing. 

After  varnishing  and  drying,  the  backs  of  the  plates  are  carefully 
cleaned  and  put  away  in  boxes  or  closets,  secured  against  dust  and 
moisture. 

Sometimes  the  collodion  film  cracks  on  drying  the  plate;  this  takes 
place  particularly  when  the  film  is  too  thin,  or  with  old  plates  which 
have  not  been  polished  well. 

Very  old  collodion  shows  the  same  properties.  If  such  cracks  show 
themselves,  the  film  may  be  treated  while  still  damp  with  alcohol  of 
80  degrees,  and  varnished  cold.  When  dry,  a  second  coat  of  varnish  is 
applied. 


SUCCESSION  OF  THE  DIFFERENT 

IN  THE 

NEGATIVE  AND  POSITIVE 


OPERATIONS 
PROCESSES. 


SECTION  I. 
THE    NEGATIVE  PROCESS. 
a.  PREPARATIONS. 

Placing  the  plates  in  acid.    Washing  and  drying,  or  albumenizing. 
Filtering  the  silver-bath  and  removing  the  scum. 
Making  the  developer,  intensifier,  and  fixing  solution. 
Dipper,  plate-holder,  clean  glasses,  and  filtering-paper  should  always  be 
in  readiness. 

Preparation  of  the  model  and  the  camera  (focussing). 

b.  OPERATIONS. 

Cleaning  the  plates  (with  ammonia  and  towels). 

Dusting  (the  duster  not  to  be  placed  on  the  tables). 

Pouring  the  collodion  (the  collodion  must  not  be  shaken,  and  the  bottle 

must  be  re-closed  immediately). 
Drying  the  film  (until  the  last  drop  commences  to  congeal,  and  the 

film  on  the  corner,  where  the  collodion  has  been  poured  off,  tears 

in  patches). 

Immersion  in  the  silver-bath  (the  corner  by  which  the  plate  has  been 
held,  should  be  immersed  first,  and  when  the  silvering  is  done 
with  a  dish,  the  liquid  should  be  scummed  before  every  immer- 
sion). 

Moving  the  plate  in  the  bath  (until  the  greasy  lines  have  disappeared). 


132 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Taking  the  plate  from  the  bath  and  draining  on  clean  blotting-paper. 
Placing  pieces  of  blotting-paper  in  the  plate-holder. 
Placing  the  plate  in  the  holder. 
Closing  the  holder. 

Carrying  the  plate  to  the  atelier  (holding  the  holder  vertically). 
Readjustment  of  the  focus  (to  see  if  anything  has  been  changed). 
Placing  the  holder  in  the  camera  (without  shaking). 
Opening  the  shutter  (carefully). 

Exposure  (opening  and  closing  the  lens  without  shaking  the  camera). 

Closing  the  shutter  (easily). 

Carrying  the  plate  to  the  dark-room  (vertically). 

Pouring  the  developer  into  a  small  glass  (as  directed). 

Taking  the  plate  from  the  holder  (cautiously). 

Pouring  the  developer  on  the  upper  corner  of  the  plate  (moving  the 

plate  and  controlling  the  development). 
Short  washing. 

Intensifying  (continually  watching,  by  transmitted  light). 

Short  washing. 

Fixing. 

Long-continued  washing. 
Drying. 

Warming  the  plate. 
Varnishing. 

These  are  the  twenty-eight  consecutive  operations  which  have  to  be 
performed  with  perfect  accuracy  when  we  wish  to  obtain  a  perfect 
picture. 

• 

SECTION  II. 

i 

THE  CARE  OF  THE  PHOTOGRAPHIC  APPARATUS  AND 
THE  CHEMICALS. 

In  the  previous  chapter  we  have  especially  explained  the  practice 
of  the  negative  process,  the  arrangement  of  the  apparatus,  the  com- 
position of  the  chemicals,  and  all  the  precautions  and  little  tricks 
which  are  necessary  for  the  successful  practice  of  the  various  photo- 
graphic processes. 

If  the  relations,  under  which  the  respective  operations  are  carried 
on,  would  always  remain  the  same,  it  would  hardly  be  necessary  to 
add  anything  to  the  previous  chapter.    But  all  things  in  this  world 


CARE  OF  THE  CAMERAS. 


133 


are  subject  to  endless  variations,  and  this  general  law  extends  of 
course  to  photographic  apparatus  and  chemicals.  Unfortunately, 
these  changes  are  generally  for  the  worse  instead  of  for  the  better, 
and  necessitate  a  constant  mending  and  doctoring  to  keep  the  respec- 
tive articles  in  their  proper  condition.  The  labor  necessary  to  ac- 
complish this  end,  we  will  condense  under  the  title  care,  and  we  will 
commence  with 

THE  CARE  OF  THE  PHOTOGRAPHIC  LENSES. 

Of  all  the  necessities  of  the  atelier,  the  photographic  lenses  appear 
to  be  the  most  lasting,  excepting  of  course  their  liability  to  breakage. 
However,  they  are  also  exposed  to  danger,  particularly  through  the 
influence  of  dust.  This  substance  penetrates  through  the  slit  for  the 
stops  into  the  interior  of  the  tube,  collects  on  the  lenses,  and  absorbs 
of  course  a  portion  of  the  light.  Openings  through  which  dust  can 
penetrate  should  be  kept  closed  as  much  as  possible.  The  objectives 
should  occasionally  be  taken  apart,  and  the  surfaces  of  the  lenses 
should  be  cleaned  with  soft  leather.  Sometimes  the  interior  black 
mounting  of  the  lenses  suffers ;  the  black  coating  rubs  off,  becomes 
glossy,  and  gives  rise  to  unpleasant  reflections.  The  bright  spots 
should  be  brushed  over  with  a  solution  of  shellac  to  which  lampblack 
has  been  added. 

It  must  be  remembered  that  flint-glass  is  softer  than  crown-glass, 
and  must  be  handled  with  greater  care. 

CARE  OF  THE  CAMERAS. 

The  photographic  cameras,  as  well  as  the  lenses,  are  exposed  to  the 
injurious  influences  of  dust.  Frequently,  when  the  bellows  are  pushed 
in,  a  quantity  of  dust  escapes  from  the  interior,  which  collects  on  the 
plate  and  gives  rise  to  holes  and  spots.  Frequent  dusting  with  duster 
and  bellows  is  here  necessary. 

The  plate-holders  are  the  most  exposed  to  injury  and  destruction. 
The  silver  solution  from  the  moist  plates  drips  from  the  plate,  collects 
on  the  holder,  penetrates  into  the  wood,  and  causes  decomposition. 
Many  peculiar  organic  substances  are  thus  formed,  which  dissolve  in 
the  liquid  which  drips  from  a  new  plate,  and  on  long  exposure  pene- 
trate into  the  collodion  film,  and  on  development  give  rise  to  the  so- 
called  "  mossy  "  spots. 

This  phenomenon  manifests  itself  most  frequently  with  composition 
corners,  as  these  offer  to  the  silver  solution  a  wider  road  into  the  in- 
terior of  the  wood  than  corners  of  solid  glass  or  silver  wire.  The 


134 


THE  PRACTICE  OF  PHOTOGRAPHY. 


lower  corners  of  the  plate-holder  are  particularly  exposed  to  this  in- 
fluence. 

To  prevent  the  saturation  of  the  plate-holder  with  silver  solution,  it 
is  best  to  dip  the  lower  corners  of  the  holder  into  melted  paraffin,  or 
to  varnish  them  with  asphalt  varnish. 

The  perfectly  dry  and  clean  corners  of  the  plate-holder  should  be 
dipped  for  five  minutes  into  melted  paraffin ;  this  preserves  the  wood 
to  an  extraordinary  degree. 

When  we  wish  to  prepare  old  plate-holders  in  the  same  manner,  the 
silver  solution,  which  has  previously  penetrated  into  the  wood,  must 
first  be  removed ;  for  this  purpose  the  lower  corners  of  the  holder 
should  be  immersed  for  from  five  to  ten  minutes  in  hot  water  ;  after 
this  they  should  be  carefully  washed  under  a  spigot,  dried,  and  after- 
wards immersed  in  melted  paraffin. 

When  the  holders  have  completely  cooled,  the  superfluous  paraffin 
should  be  scraped  off. 

Remele  recommends,  in  place  of  paraffin,  the  varnishing  of  the 
holder.  This  mode  of  preservation,  however,  has  to  be  repeated 
monthly,  and  it  only  forms  a  substitute  where  paraffin  is  not  acces- 
sible. 

The  utmost  cleanliness  is  necessary  for  the  preservation  of  the 
plate-holder.  After  every  exposure,  the  adhering  liquid  should  be 
removed  with  blotting-paper,  and  the  holder  should  be  frequently 
washed  under  the  tap. 

New  holders  give  trouble  very  often  by  the  detachment  of  small 
particles  of  wood  or  varnish,  and  do  not  become  perfectly  reliable 
until  all  these  particles  have  been  brushed  away  by  continued  prac- 
tice. 

All  the  wooden  parts  of  the  apparatus  should  be  provided  with 
brass  strips  to  prevent  warping. 

In  hot  summers  the  very  best  of  apparatus  will  warp.  Placing 
moist  blotting-pads  inside  the  cameras,  or  covering  them  with  moist 
cloths  or  blankets,  is  the  best  remedy,  and  it  is  particularly  recom- 
mended to  landscape  photographers. 

CARE  OF  THE  GLASS  PLATES. 

Fresh  plates  are  generally  stored  away  with  layers  of  paper  be- 
tween them.  But  even  the  best  paper  is  not  clean  enough,  and  leaves 
an  impression  on  the  plate  when  it  remains  sufficiently  long  in  con- 
tact with  it. 


CARE  OF  THE  GLASS  PLATES. 


135 


For  preserving  polished  or  albumenized  plates,  the  plate-boxes  are 
used ;  the  sides  of  these  boxes  are  furnished  with 
grooves,  /,  /,  Fig.  65,  in  which  the  plates  are  FlG- 65- 

placed.    Care  should  be  taken  to  keep  the  grooves  ^ 
as  clean  as  possible,  and  that  they  are  wide  enough 
to  give  the  plates  some  play.    We  sometimes  meet  'p? 
with  plate-boxes  at  the  stock  depots  which  are  a 


large  and  high  enough,  but  the  grooves  are  so 
narrow  that  a  thick  plate  is  only  pushed  into  it 
with  difficulty,  which  often  causes  breakage.  A 
disadvantage  is  that  finished  and  varnished  collodion  plates  and  dry 
plates  easily  become  rubbed  off  by  inserting  them  into  the  boxes.  In 
England,  metal  boxes  with  grooves  that  have  an  acute  angle  are 
much  in  use,  and  these  are  free  from  the  above  disadvantage  (see  Z, 
Fig.  65).    It  is  self-evident  that  the  prepared  surface  has  to  be 
placed  in  the  direction  a.    About  plate-boxes  becoming  soiled,  see 
remarks  thereon.    Instead  of  them  we  can  use  strips  of 
pasteboard  for  the  finished  negatives ;  they  are  bent  thus  :      Fig.  66. 
AAAAAAA.    The  plates  are  placed  between  two  such     f ?]  -'p1 
strips  as  shown  in  Fig.  66,  and  tied  together.  %  j  j 

Plates  that  have  been  cleaned,  and  are  not  used  the  ^  \\  j  j 
same  day,  should  be  rubbed  over  with  chamois  leather  vmHi 
before  they  are  used. 

Cleaned  plates  for  travelling  should  be  packed  with  margins  of 
pasteboard,  when  no  plate-boxes  are  at  the  disposal  of  the  photographer. 
Such  margins  are  easily  made,  and  the  centre  of  the  plates  will  be 
protected. 

Great  care  should  be  taken  not  to  scratch  the  plates.  They  should 
never  be  laid  flat  on  the  table,  and  they  should  only  be  rubbed  with 
cloths  which  are  perfectly  free  from  dust.  We  should  never  forget  to 
clean  the  rough  margins.  Plates  that  have  been  used  once  before  re- 
quire a  different  treatment. 

When  the  picture  on  being  developed  proves  useless,  the  plate 
should  be  cleaned  at  once,  dried  with  a  towel,  and  re-polished. 

Plates  over  which  the  chemicals  have  been  poured  should  never  be 
allowed  to  dry.  By  permitting  salts  or  even  water  to  dry  upon  them, 
they  may  become  affected  to  a  degree  that  even  an  immersion  in  acid 
or  caustic  soda  will  fail  to  clean  them. 

Fixed  plates,  that  have  not  been  varnished,  should  be  placed  at 
once  into  nitric  acid. 

Varnished  plates,  that  are  unfit  for  use,  should  be  placed  for  twelve 
hours  in  a  concentrated  solution  of  carbonate  of  soda ;  they  should 


136 


THE  PRACTICE  OF  PHOTOGRAPHY. 


then  be  washed,  and  when  the  film  has  become  perfectly  loose,  the 
plates  should  be  placed  for  a  short  time  in  acid  previous  to  being 
cleaned.  By  the  abrasion  of  the  corners  of  the  plates,  a  deposit  of 
glass-sand  will  form  at  the  bottom  of  the  dishes,  which  will  scratch 
the  plates ;  it  is,  therefore,  better  to  place  flat  pieces  of  wood  at  the 
bottom  of  the  dishes,  and  to  let  the  plates  rest  on  them. 

When  immersing  and  when  removing  the  plates  care  should  be 
taken  not  to  scratch  them. 

CARE  OF  THE  COLLODION. 

Collodion  forms  the  basis  of  the  photographic  negative  pictures;  it 
is  for  the  photographer  of  more  importance  than  the  paper  for  the 
draughtsman.  It  not  only  acts  mechanically  by  fixing  the  sensitive 
film  to  the  glass,  but  also  chemically  by  containing  besides  the  indif- 
ferent pyroxylin  a  whole  line  of  products  of  disintegration,  which 
have  a  material  influence  on  the  chemical  and  physical  properties  of 
the  film. 

The  care  of  the  collodion  is  consequently  of  much  importance  for 
the  photographer  who  desires  to  secure  equal  results  always. 

The  changes  which  iodized  collodions  suffer  manifest  themselves  by 
a  change  of  color,  first  yellow  and  then  red,  and  by  a  decrease  of  sen- 
sitiveness. In  these  changes  free  iodine,  which  remains  dissolved  in 
the  collodion,  separates  from  the  liquid,  and  gives  rise  to  the  forma- 
tion of  free  nitric  acid  in  the  bath,  which  will  impair  the  sensitiveness 
of  the  plate. 

The  salts  of  cadmium  have  the  least  tendency  to  turning  the  collo- 
dion red,  while  the  salts  of  ammonium  have  the  greatest.  While  the 
collodion  turns  red,  it  becomes  more  fluid,  and  finally  so  limpid  that 
it  does  not  secure  a  homogeueous  or  tenacious  film. 

It  has  been  recommended  to  shake  collodion  which  has  turned  red, 
with  carbonate  of  soda,  respectively  with  metallic  cadmium,  and  to 
let  it  settle.  These  bodies  will  absorb  the  iodine  and  restore  the  bright 
color  of  the  collodion,  but  at  the  same  time  the  plates  will  have  a  ten- 
dency to  fogginess,  probably  in  consequence  of  the  formation  of  alka- 
line salts,  which  are  partially  soluble  in  collodion,  for  instance  Cdl 
and  CdO. 

It  is  much  more  preferable  to  mix-  the  red  collodion  with  cadmium 
collodion.  The  latter  will  remain  white  for  months ;  it  is  somewhat 
thick,  and  by  mixing  it  with  red  collodion  we  will  get  the  desired 
consistency  and  color  very  often. 

Any  one  who  works  with  cadmium  collodion  exclusively  will  very 


CARE  OF  THE  COLLODION. 


137 


seldom  or  never  complain  about  red  collodion.  For  other  mixtures 
which  have  a  tendency  to  turning  red,  it  is  recommended  to  preserve 
the  plain  collodion  and  the  iodizer  separately. 

In  this  case  the  fluids  are  mixed  in  such  quantities  as  experience 
has  taught  will  be  consumed  in  a  short  space  of  time. 

Besides  the  disengagement  of  iodine  a  change  in  the  proportion  of 
alcohol  and  ether  takes  place,  as  well  as  the  introduction  of  impuri- 
ties, such  as  dust,  etc. 

The  excess  of  collodion  which  has  been  poured  on  the  plate  is^gen- 
erally  returned  to  the  bottle.  But  this  excess  has  lost  a  part  of  its 
dissolving  media  by  evaporation,  and  of  course  more  of  the  fugitive 
ether  than  of  the  less  fugitive  alcohol. 

Hence,  what  is  poured  back  into  the  bottle  is  thicker  and  richer  in 
alcohol.  With  very  careful  management  this  does  not  matter  much; 
under  favorable  circumstances  a  bottle  of  collodion  can  be  used  all 
but  a  very  small  remnant.  And  if  this  remnant  should  be  too  thick, 
it  should  be  diluted  with  y1^  of  ether. 

But  much  more  annoying  than  this  loss  of  fluidity  is  the  accumula- 
tion of  dust  and  other  impurities.  Small  traces  of  dust  are  washed 
into  the  collodion-bottle  with  the  excess  which  is  returned  from  the 
plate ;  with  every  plate  this  quantity  is  increased,  and  finally  the  col- 
lodion will  work  uneven. 

This  is  more  frequently  the  case  when  travelling,  where  we  have  to 
contend  more  with  dust  than  at  home ;  the  annoyance  is  increased 
also  with  larger  plates. 

The  rough  corners  of  the  plates  exercise  a  very  injurious  influence, 
as  they  form  receptacles  for  dust  and  other  impurities,  which  is  only 
too  easily  overlooked  and  returned  to  the  collodion.  It  happens  quite 
frequently  that  the  grooves  of  the  plate-boxes  are  filled  with  impuri- 
ties, all  of  which  help  to  spoil  the  collodion. 

All  these  evils  can  be  avoided  by  returning  the  excess  of  collodion 
to  a  separate  bottle ;  this  collodion  is  by  no  means  useless ;  it  should 
be  left  to  settle  for  a  week  or  so,  and  the  pure  liquid  can  then  be  de- 
canted and  used. 

That  the  neck  of  the  collodion-bottle  should  always  be  kept  clean 
is  a  matter  of  course.  A  bell-glass  should  be  placed  over  the  stock- 
bottle.  When  no  special  collodion-bottle  is  employed,  the  neck  of  the 
bottle  should  be  kept  perfectly  clean  by  wiping  it  with  the  finger,  and 
the  first  few  drops  should  be  thrown  away  before  pouring  the  collodion 
on  the  plate. 

The  bottle  should  be  corked  immediately  after  the  plate  has  been 
collodionized. 


138 


THE  PRACTICE  OF  PHOTOGRAPHY. 


THE  CARE  OF  THE  SILVER-BATH. 

A  correctly  prepared  silver-bath  can  be  kept  in  good  order  for  a 
long  time  with  careful  treatment.  The  conditions  are  to  keep  it  as 
nearly  as  possible  free  from  mechanical  and  chemical  impurities.  The 
former  present  themselves  very  soon  in  the  shape  of  detached  pieces  of 
the  film  and  dust. 

Frequent  filtering  is  consequently  a  matter  of  course,  and  still  it 
does  sometimes  happen  that  this  does  not  purify  a  bath,  but  has  just 
the  contrary  effect.  A  photographer  of  my  acquaintance  tells  me  of 
such  a  case.  He  unfortunately  employed  a  filtering-paper  contain- 
ing a  large  quantity  of  the  salts  of  sulphuric  acid.*  These  are  thrown 
into  the  bath  and  give  rise  to  the  formation  of  sulphate  of  silver, 
which  attaches  itself  in  needle-shaped  crystals  to  the  plate,  and  causes 
spots. 

A  very  pure  filtering-paper  should  be  selected.  Sometimes  a  greasy 
film  remains  on  the  surface  after  filtering.  In  dishes  this  does  not 
escape  observation  as  easily  as  in  the  bath.  The  film  should  be  re- 
moved with  strips  of  writing-paper,  which  are  drawn  over  the  liquid. 

If  a  silver-bath  did  not  suffer  any  other  damage  in  the  preparation 
of  the  plates  than  the  loss  of  silver,  it  would  be  possible  to  use  it  to 
the  last  drop,  similar  to  a  positive  bath ;  but  this  is  unfortunately  not 
the  case. 

Every  collodion,  besides  the  salts  of  iodine  and  bromine,  contains 
pyroxylin,  and  also  the  organic  products  of  decomposition.  With 
every  plate  a  quantity  of  these,  as  well  as  alcohol  and  ether,  is  left  in 
the  bath,  and  after  awhile  it  will  contain,  besides  the  salts  of  silver, 
the  salts  of  cadmium,  alcohol,  and  ether,  the  organic  products  of  de- 
composition from  the  collodion  and  iodide  of  silver,  and  acetic  acid, 
formed  by  the  oxidation  of  the  alcohol. 

No  wonder  then  that  it  changes  rapidly;  that  it  soon  ceases  to 
yield  strong  and  vigorous  plates,  and  furnishes  weak  negatives  in- 
stead. Finally  a  point  is  reached,  where  the  iodide  of  silver,  which 
has  collected  in  the  bath,  collects  on  the  plates  and  gives  rise  to  pin- 
holes. This  occurs  particularly  in  summer-time  with  a  high  tempera- 
ture. 

When  such  a  bath  is  tested  for  the  amount  of  silver  which  it  con- 


*  To  test  the  paper  for  these  substances,  it  is  necessary  to  soak  it  in  water, 
to  pour  off  the  clear  liquid,  and  to  add  a  solution  of  nitrate  of  baryta;  when 
the  salts  of  sulphuric  acid  are  present,  a  precipitate  of  sulphate  of  baryta  will 
be  formed. 


CARE  OF  THE  SILVER-BATH. 


139 


tains,  it  is  generally  found  to  be  very  rich  in  that  substance,  having 
often  not  lost  more  than  one-half  per  cent,  apparently. 

It  is  evident  that  such  a  bath  could  be  restored  to  its  former  use- 
fulness if  we  were  able  to  remove  the  above-enumerated  impurities. 

Want  of  sensitiveness  is  occasioned  by  the  amount  of  acetic  acid 
which  forms  in  course  of  time  in  the  bath  from  the  alcohol  and  ether 
acid,  or  by  the  presence  of  organic  matters.  Acid  can  be  remedied  by 
neutralizing  the  bath.  Formerly  the  oxide  of  silver  was  frequently 
used  for  this  purpose.  This,  however,  should  be  rejected,  as  its  action 
is  too  slow.  Carbonate  of  lime  is  not  to  be  recommended  either,  when 
it  is  employed  in  excess,  as  is  generally  the  case,  for  it  precipitates  a 
portion  of  the  silver.  The  best  remedy  is  to  employ  pure  carbonate 
of  soda. 

One  part  is  dissolved  in  ten  parts  of  water,  and  this  is  added  drop 
by  drop  to  the  bath.  A  precipitate  is  formed  which,  on  agitating  the 
liquid,  will  disappear  again  completely ;  a  second  drop  is  added,  and 
so  on  until  the  precipitate  will  no  longer  disappear  on  shaking  the 
bath. 

When  the  bath  is  now  tested,  we  will  find  that  its  reaction  has  be- 
come slightly  alkaline.  It  is  filtered,  and  to  the  filtrate  one  or  two 
drops  of  diluted  nitric  acid  are  added  (one  part  acid  to  five  water) ;  a 
plate  is  now  taken,  and  if  it  shows  any  fogginess,  more  acid  is  added, 
until  the  plate  becomes  clear. 

This  method  of  testing  appears  somewhat  complicated,  and  some 
may  think  that  litmus-paper  would  answer  as  well ;  but  this  is  not  the 
case.    With  the  latter  we  often  get  too  much  acid  in  the  bath. 

When  an  old  bath  commences  to  yield  weak  negatives  or  to  give 
insensitive  plates,  which  besides  have  a  tendency  to  show  lines  and 
streaks,  it  generally  contains  organic  substances.  In  such  a  case  the 
addition  of  soda  would  not  do  much  good,  for  it  would  not  remove 
the  organic  substances.  Photographers  usually  neutralize  the  bath, 
and  place  it  afterwards  in  the  sun.  This  is  very  good  when  we  have 
plenty  of  sunlight ;  unfortunately,  however,  this  is  not  always  to  be 
had,  and  the  perfect  purification  is  slow,  requiring  sometimes  a  whole 
day. 

Under  these  circumstances  permanganate  of  potash,  which  was  first 
proposed  by  Dr.  Jacobsen,  is  preferable ;  it  was  first  tried  by  Mr.  E. 
Crooks. 

This  splendid  preparation  has  lately  been  brought  into  the  market 
in  beautiful  black  crystals,  which,  when  dissolved  in  water,  impart  to 
it  an  intensely  deep  red  color.  The  solution  itself  is  sensitive  to  light, 
and  decomposes  slowly,  forming  a  brown  precipitate  (peroxide  of 


140 


THE  PRACTICE   OF  PHOTOGRAPHY. 


manganese).  Organic  substances  discolor  the  liquid  rapidly;  the 
former  oxidize,  and  the  permanganic  acid  is  reduced  to  peroxide  of 
manganese, 

Mn207  =  2Mn02  +  03, 

which  separates  with  brownish  color.  This  decomposition  takes  place 
already  in  filtering  through  paper. 

This  property  of  destroying  organic  bodies  makes  this  substance 
very  valuable  in  removing  organic  matter  from  the  bath.  One  part 
of  the  permanganate  is  dissolved  in  fifty  parts  of  water.  From  this 
solution  is  added  at  first  one  drop  to  the  bath  which  is  to  be  restored. 
If  it  contains  much  organic  matter,  the  first  drops  will  almost  imme- 
diately be  discolored :  it  is  then  added  in  drops  again  and  shaken, 
and  so  over  again  until  the  last  drop  is  no  longer  discolored,  and  the 
bath  assumes  a  slight  rose  tinge,  which  will  last  for  about  a  minute 
(after  a  longer  period  the  tinge  from  the  permanganate  will  always 
disappear).    Too  much  permanganate  injures  the  bath. 

When  a  great  deal  of  organic  matter  has  accumulated  in  the  bath, 
a  brownish  color  will  be  perceptible  beside  the  rose  color ;  the  former 
is  occasioned  by  peroxide  of  manganese. 

The  bath  is  now  filtered.  When  only  a  little  of  the  permanganate 
has  been  used,  it  will  generally  work  well  without  further  addition. 

When  a  large  quantity  has  been  added,  the  potash  will  act  as  a 
neutralizes  and  one  or  more  drops  of  nitric  acid  have  to  be  added, 
until  all  tendency  to  fog  has  disappeared. 

In  some  cases,  by  the  treatment  with  permanganate  of  potash,  the 
organic  substances  have  been  oxidized,  but  not  destroyed  ;  if  so,  the 
organic  matters  may  be  destroyed  by  evaporation  of  the  bath,  and  the 
melting  of  the  solid  residue.  This  work  we  do  not  recommend;  better 
change  such  a  bath  and  make  a  positive  bath  from  it,  and  take  a 
new  one  in  use. 

Evaporation  is  best  done  in  a  porcelain  dish  over  a  Berzelius  (alco- 
hol) lamp,  or  a  gaslight. 

As  soon  as  all  the  water  has  evaporated,  the  silver  salt  becomes  a 
tough  mass,  from  which  reddish  fumes  escape.  The  gray  color  is 
caused  by  precipitated  metallic  silver.  The  dish  is  now  allowed  to 
cool ;  the  solid  salt  is  dissolved  in  a  little  water  placed  on  the  fire, 
and  when  it  boils,  a  few  drops  of  nitric  acid  are  carefully  added. 
The  cloudy  mass  on  being  heated  will  all  at  once  become  as  clear  as 
water. 

Evaporate  once  more  to  dryness,  and  heat  carefully  to  the  melting- 
point  ;  let  it  cool,  and  now  dissolve  the  salt  in  ten  parts  of  water. 


CARE  OF  THE  SILVER-BATH. 


141 


When  the  bath  gives  veiled  pictures,  acid  should  be  added,  as  has 
been  described  above. 

Another  impurity  of  the  bath  is  an  excess  of  iodide  of  silver,  which 
forms  most  readily  in  a  high  temperature.  Iodide  of  silver  does  not 
separate  as  easily  from  a  warm  solution  as  from  a  cold  one.  When 
the  crystals  are  large,  they  form  a  mealy  covering,  and  the  plate  will 
show  numerous  yellow  spots  after  development ;  when  they  are  small, 
they  give  rise  to  pinholes. 

To  remove  iodide  of  silver,  the  bath  should  be  diluted  with  thrice 
its  volume  of  distilled  water,  and  well  shaken.  The  iodide  of  silver, 
which  is  only  slightly  soluble  in  the  diluted  bath,  precipitates  almost 
entirely.  It  will  only  be  necessary  to  filter  the  liquid,  and  to  evapo- 
rate it  down  to  the  original  volume.  Very  often  the  bath  contains  an 
excess  of  iodide  of  silver  and  organic  substances ;  in  this  case  it  should 
first  be  diluted,  filtered,  and  treated  with  the  permanganate. 

In  the  presence  of  organic  substances,  the  iodide  of  silver  will  sepa- 
rate much  more  rapidly  than  without  it. 

Another  method  to  restore  a  bath  which  precipitates  iodide  of  silverj 
consists  in  adding  to  the  bath  a  fresh  solution  of  silver,  free  from 
iodine,  and  of  the  same  strength  as  the  bath.  In  warm  weather  this 
will  answer  for  a  short  time  only.  It  is  best  to  prevent  the  precipita- 
tion of  iodide  of  silver  by  maintaining  the  bath  at  a  low  temperature; 
This  can  be  done  by  cold  water  or  ice,  or,  when  neither  is  handy,  by 
wrapping  the  bath  in  a  dark,  wet  cloth,  and  exposing  it  to  a  current 
of  air. 

These  are  the  most  important  methods  of  taking  care  of  the  bath. 
One  impurity,  however,  cannot  be  removed  by  them,  L  e.,  the  products 
of  the  decomposition  of  the  salts  of  iodine,  the  salts  of  cadmium,  anc) 
alkalies  combined  with  nitric  acid ;  when  these  are  present  in  percep- 
tible quantities,  not  one  of  the  methods  mentioned  for  restoring  the 
bath  will  work  satisfactorily,  and  it  will  always  produce  pictures  weak 
and  without  delicacy. 

In  such  a  case  it  is  always  best  to  remove  the  iodide  of  silver,  as 
has  been  explained  above,  by  diluting  it  with  twice  its  volume  of 
water ;  next  to  evaporate  it  till  dry,  and  melt  as  abovementioned.  The 
dry  salt  is  dissolved  in  8-10  parts  of  water,  and  used  as  a  positive  bath. 
This  is  much  more  rational  than  the  ordinary  way  of  throwing  such 
baths  into  the  waste-barrel  for  reduction. 

The  practical  photographer  will  do  well  to  have  always  two  silver 
baths  on  hand  (one  for  present  use,  the  other  as  a  reserve  in  case  an 
accident  should  happen  to  the  first),  and  very  often  it  is  preferable  to 


142 


THE  PRACTICE  OF  PHOTOGRAPHY. 


make  a  new  bath,  as  generally  speaking  a  "  doctored  "  bath  does  not 
work  as  well  as  a  new  one. 

In  many  instances  the  use  of  two  negative  baths  is  advisable,  an 
old  one  for  silvering  the  plates,  and  a  new  one  into  which  the  silvered 
and  well-drained  plates  are  dipped.  The  plate  receives  in  this  way  a 
coating  of  pure  silver  solution,  and  gives  a  finer  picture  than  with  the 
old  bath  alone.  In  course  of  time  the  second  bath  also  becomes  con- 
taminated, and  after  awhile  the  second  bath  takes  the  place  of  the  first, 
and  a  new  one  is  made.  The  used-up  first  bath  is  used  for  a  printing 
bath. 

CARE  OF  THE  DEVELOPER. 

The  protosulphate  of  iron  in  solution  will  soon  turn  red,  in  conse- 
quence of  the  formation  of  an  ineffectual  oxidized  salt.  Such  a  red 
solution  contains  consequently  a  less  quantity  of  the  active  salts  of 
iron  than  one  that  has  been  freshly  prepared.  This  is  an  advantage 
when  we  have  to  develop  pictures  without  half  tones.  For  this  pur- 
pose an  old  developer  is  to  be  preferred,  but  for  plates  with  half  tone, 
as  for  instance  portraits,  a  freshly  made  developer  is  the  most  advan- 
tageous. When  a  developer  has  to  be  kept  for  a  long  time,  as  in 
travelling,  sulphate  of  iron  and  ammonia  should  be  taken  instead  of 
protosulphate  of  iron. 

CARE  OF  THE  INTENSIFIER. 

Watery  pyrogallic  solution  oxidizes  rapidly  when  exposed  to  the 
air ;  it  should  be  prepared  fresh  every  day.  The  solution  of  silver 
and  citric  acid  will  keep  for  more  than  a  week.  Citric  acid  appears, 
however,  to  be  liable  to  decomposition,  and  is  apt  to  cause  bluish 
veils  on  the  negative ;  an  addition  of  1  per  cent,  of  fresh  citric  acid 
will  remedy  this. 

CARE  OF  THE  FIXING  BATH. 

The  solution  of  cyanide  of  potassium,  if  used,  should  be  prepared 
fresh  every  day. 

Hyposulphite  of  soda  solution  will  keep  longer.  Continued  use 
and  acids  will  cause  decomposition.  It  should  be  prepared  fresh  every 
four  or  five  days. 

CARE  OF  THE  VARNISH. 

Varnish  is  subject  to  similar  changes  as  the  collodion.  It  becomes 
thick  by  evaporation  of  the  alcohol,  and  dusty  by  the  varnish  which 


VEILS  OR  FOG. 


143 


is  poured  back  from  the  plate  into  the  bottle.*    It  is  advisable  to 
pour  the  excess  of  varnish  from  the  negative  into  a  separate  bottle. 
It  can  be  diluted  with  alcohol,  filtered,  and  used  like  fresh  varnish. 
On  the  eating  away  of  the  collodion  film,  see  page  129. 

CARE  OF  THE   FINISHED  NEGATIVE 

Will  be  explained  in  the  chapter  on  the  positive  process. . 
SECTION  III. 

FAILURES  IN  THE  NEGATIVE  PROCESS. 

The  number  of  failures  in  the  negative  process  is  legion.  The 
cause  is  on  the  one  hand  the  changes  and  variations  to  which  our 
apparatus  and  solutions  are  liable,  and  about  failures  occurring  from 
this  source  we  have  spoken  in  the  previous  chapter,  under  the  head- 
ing, "  The  Care  of  the  Camera,"  etc. 

Those  who  have  carefully  studied  this  chapter,  and  know  how  to 
apply  what  they  have  learned,  will  readily  avoid  many  of  the  causes 
of  ill-success.  On  the  other  hand,  want  of  attention  or  want  of  skill  of 
the  operator  is  often  the  cause  of  trouble. 

If  we  do  not  proceed  with  our  labor  with  the  greatest  conscientious- 
ness, we  will  always  have  to  contend  with  failures.  Some  of  them,  as, 
for  instance,  wrong  pose,  faulty  illumination,  too  long  or  too  short  an 
exposure,  will  happen  to  every  beginner,  and  can  only  be  overcome 
by  long  practice. 

The  failures  in  the  negative  process  manifest  themselves  generally  on 
developing  the  plate.  It  is  therefore  imperative  not  to  intensify  or  to 
finish  until  after  the  plate  has  been  washed  after  being  developed,  the  back 
carefully  cleaned,  and  closely  scrutinized  for  any  apparent  faults. 

1.  VEILS  OR  FOG. 

The  main  trouble  is  the  fogging  of  the  plate.  This  is  a  general  pre- 
cipitate of  silver  which  covers  the  whole  plate,  light  as  well  as  shade. 
The  causes  are  manifold,  a.  The  so-called  dark-room  admits  too  strong 
light  (the  author  works  only  with  subdued  lamplight) ;  b.  The  plate 
has  been  exposed  to  too  intense  lamplight ;  c.  The  camera  or  the 


*  It  is  well  to  dust  the  plate  previous  to  varnishing  with  the  camel-hair 
pencil,  and  loose  pieces  of  collodion  film  at  the  edges  of  the  plate  should  be 
removed. 


144 


THE  PRACTICE  OF  PHOTOGRAPHY. 


plate-holder  has  holes  (in  the  latter  case  the  spots  will  always  be 
opposite  the  opening)  ;  d.  Bright  light  enters  the  objective  (this  hap- 
pens frequently  when  the  lens  is  placed  opposite  to  an  opening  in  the 
curtain  or  the  bright  sky) ;  e.  The  collodion  is  alkaline  (in  this  case 
a  few  drops  of  tincture  of  iodine  will  remedy  the  evil) ;  /.  The  ni- 
trate bath  is  alkaline  (remedy,  addition  of  acid)  ;  g.  The  nitrate  bath 
contains  organic  substances  (in  this  case  the  plate  is  generally  very 
insensitive — remedy,  permanganate  of  potash)  ;  h.  The  bath  contains 
subnitrate  of  silver  formed  by  nitrous  acid.  When  this  happens, 
the  bath  should  be  discarded,  and  used  as  a  positive  bath.  Other 
causes  are  arranged  according  to  their  origin. 

2.  FAILURES  DUE  TO  THE  MODEL. 

Yellow  spots,  scarcely  visible  to  the  naked  eye,  as  freckles  on  the 
face,  spots  of  iron-rust  in  the  paper,  manifest  themselves  in  the 
photograph  in  a  remarkable  manner,  and  are  sometimes  ascribed  to 
the  chemicals. 

3.  FAILURES  DUE  TO  CLEANING  AND  POLISHING  THE  PLATE 

Manifest  themselves  partially  by  breathing  on  the  plate.  The  plate 
takes  the 'breath  unevenly.  Some,  however,  become  visible  only  after 
development. 

1.  Precipitates  of  a  silvery  lustre,  between  the  collodion  film  and 
the  glass  (best  visible  from  the  back),  are  caused  by  badly  acidified 
plates,  or  with  old  plates  which  have  frequently  been  used  and  care- 
lessly treated.  Remedy,  immersion  for  twelve  hours  in  chromate  of 
potash  solution.  If  this  remedy  fails,  such  plates  may  still  be  used, 
but  should  be  albumenized  (see  page  116). 

2.  Mossy-looking  designs,  proceeding  mostly  from  the  lower  corner. 
Cause,  dirty  plate-holder.  Remedy,  wash  the  plate-holder  with  warm 
water,  wipe  it  dry,  and  coat  with  asphalt  varnish.  Coating  with  neg- 
ative varnish  will  also  remedy  it,  but  it  does  not  last  long. 

3.  Dirt  along  the  margin  of  the  plate,  or  spots  which  extend  more 
or  less  to  the  centre,  are  caused  by  insufficient  cleaning  of  the  rough 
edges  of  the  plate,  or  by  becoming  soiled  later  by  resting  the  plate  on 
dirty  substances  (paper,  table,  plate-holder,  etc.),  or  by  handling  them 
with  dirty  fingers. 

4.  Polishing  streaks  show  very  plainly,  by  being  reproduced  in  the 
direction  of  the  polishing  motion.  Cracks  in  the  glass  give  frequent 
rise  to  streaks  when  the  polishing  powder  settles  into  them. 


FAILURES  DUE  TO  THE  COLLODION. 


145 


5.  Bright  irregular  spots  and  short  lines  are  caused  by  dust  or 
woody  fibre  falling  on  the  plate  when  the  plate-holder  is  opened. 

6.  Short,  black,  and  crooked  lines  (rat-tails)  are  due  to  the  use  of 
impure  albumen  in  albumenizing  the  plates. 

4.  FAILURES  DUE  TO  THE  COLLODION 

Manifest  themselves  partly  after  silvering,  partly  after  developing. 

1.  The  plate  leaves  the  bath  with  a  transparent  insensitive  margin. 
This  is  due  to  the  time  between  collodionizing  and  sensitizing  being 
too  long. 

2.  The  film  is  rotten,  and  tears  easily  in  the  bath.  Cause,  the  plate 
is  placed  too  soon  into  the  bath ;  the  collodion  is  too  old  ;  the  bath  is 
too  acid. 

3.  The  film  is  of  uneven  thickness.  Cause,  the  plate  is  coated  un- 
evenly. 

4.  Spots  which  proceed  from  the  corner  at  which  the  plate  has  been 
held.    The  collodion  should  not  touch  the  fingers. 

5.  Thick  and  thin  and  partly  streaky  spots  are  caused  by  air-bub- 
bles which  have  broken  when  the  coating  was  finished ;  also,  in  con- 
sequence of  unequal  drying,  caused  by  the  warmth  of  the  fingers  or 
the  evaporization  of  collodion  which  has  flowed  on  the  back  of  the 
plate  ;  also,  in  consequence  of  old  pyroxylin,  which  dissolves  badly. 

6.  Diagonal  streaks.  Cause,  the  plate  has  not  been  rocked  prop- 
erly while  being  coated. 

7.  Comet-like  black  spots.  Cause,  newly  iodized  and  insufficiently 
settled  collodion.  White  and  black  worm  and  snake-like  lines  occur 
also  with  new  and  insufficiently  settled  collodion,  particularly  when 
using  salts  which  do  not  dissolve  readily.  They  disappear  when  the 
collodion  has  settled  or  has  been  filtered. 

8.  Cross-like  or  tile-like  drawings  are  easily  formed  in  very  cold 
weather,  or  when  the  collodion  contains  much  water. 

9.  Black  irregular  spots.  Cause,  dirt  in  the  mouth  of  the  collodion 
bottle. 

10.  Collodion,  which  at  first  works  excellently,  gives  after  a  short 
time  faulty  plates.  Cause,  impurities  which  get  into  the  collodion  by 
pouring  the  excess  from  the  plates  back  into  the  bottle.  Remedy, 
the  excess  should  be  collected  into  a  separate  bottle. 

11.  Want  of  sensitiveness  is  met  with  in  old  and  very  red  collo- 
dion. 

12.  The  film  adheres  badly  to  the  plate.  Cause,  old  and  acid  bath, 
or  old  pyroxylin. 

10 


146 


THE  PRACTICE  OF  PHOTOGRAPHY. 


13.  The  picture  shows  a  honeycombed  structure.  Cause,  the  plain 
collodion  was  too  tough.  Remedy,  the  cotton  is  first  dissolved  in 
a  mixture  of  three  parts  ether  and  one  part  alcohol,  left  to  settle,  and 
to  the  clear  decanted  collodion  the  balance  of  alcohol  and  ether  is 
added.  , 

14.  Fog.  Cause,  the  collodion  is  alkaline.  Remedy,  add  tincture 
of  iodine.  Sometimes  the  collodion  has  been  contaminated  with 
organic  substances,  which  will  also  produce  fog,  which  cannot  be 
removed  by  any  remedy. 

5.  FAILURES  DUE  TO  THE  SILVER  BATH. 

1.  White  streaks  in  the  direction  of  the  dip,  partly  horizontal 
straight  lines  (with  a  bath),  partly  curved  (with  dishes),  and  round 
spots  caused  by  air-bubbles.  They  are  recognized  after  sensitizing. 
Cause,  want  of  steadiness  in  immersing  the  plate  (when  using  an  up- 
right bath);  too  little  solution  (when  using  a  dish). 

2.  Black  streaks  in  the  direction  of  the  dip  (particularly  with  a 
bath,  but  also  when  sensitizing  with  dishes,  the  film  being  downward). 
Cause,  the  plate  has  not  been  placed  long  enough  in  the  bath,  or  the 
bath  is  too  old  and  contaminated  with  organic  substances. 

3.  Black  streaks  originating  from  the  dipper.  Cause,  dirty  rubber 
dipper. 

4.  The  film  is  eaten  away.  Cause,  the  bath  contains  too  little  or 
no  iodide  of  silver. 

5.  Pale  and  transparent  plates,  but  little  sensitive,  are  produced 
sometimes  by  great  heat.  Remedy,  cool  the  bath  by  placing  it  in 
ice-water,  or  by  wrapping  wet  cloths  around  it  and  placing  it  in  a 
draft. 

6.  Spears,  crosses,  and  swords.  Cause,  the  bath  contains  sulphate 
or  acetate  of  silver.    Remedy,  filtering  through  clean  filtering-paper. 

7.  The  plates  appear  as  if  dusted  over  with  flour.  Cause,  large 
precipitate  of  iodide  of  silver  caused 'by  heat.  Remedy,  filtration  and 
reduction  of  temperature. 

8.  Small  holes  (pinholes).  Cause,  excess  of  iodide  of  silver. 
Remedy,  cooling  the  bath,  or  dilution  with  thrice  its  volume  of  water, 
filtering,  and  evaporating. 

9.  Black  spots,  caused  by  pressure  on  the  collodion  film,  are  fre- 
quently due  to  slight  elevations  on  the  sides  of  the  bath  or  the  bottom 
of  the  dish. 

10.  Insensitiveness  is  caused  by  great  acidity  of  the  bath,  also  by 
organic  substances.  Remedy,  neutralizing  or  treatment  with  perman- 
ganate of  potash. 


FAILURES  DUE  TO  DEVELOPMENT. 


147 


11.  Gray  and  grizzly  spots  are  caused  by  imperfect  immersing. 

12.  Fog  is  caused  by  an  alkaline  bath  or  by  organic  substances. 

13.  Weak  pictures  are  often  due  to  old  and  frequently  "  doctored  " 
baths. 

14.  The  plates  look  blue  instead  of  yellow.  Cause,  there  is  too 
little  iodide  of  silver  in  the  bath.  Remedy,  solution  of  iodide  of 
potassium  in  this  proportion :  for  every  1000  cubic  centimetres  of  bath 
solution,  take  25  cubic  centimetres  of  solution  of  iodide  of  potassium, 
of  the  strength  of  1  to  100. 

6.  FAILURES  DUE  TO  EXPOSURE. 

1.  Want  of  sharpness  or  double  outlines.  Cause,  careless  focus- 
sing, shaking  of  the  camera  or  the  objective  during  exposure. 

2.  Marbled  spots  and  drying  spots  are  caused  by  too  long  exposure 
with  a  fresh  bath,  and  in  warm  weather. 

3.  Hard  pictures — too  short  an  exposure.  Weak  pictures  are 
sometimes  caused  by  excessive  illumination  (see  also  section  5,  No. 
13). 

4.  The  picture  is  of  unequal  intensity.  Cause,  unequal  illumina- 
tion, particularly  with  drawings  (see  also  section  8). 

5.  Foggy  spots  with  drawings  and  oil-paintings  are  caused  by  re- 
flected light.    Remedy,  change  the  illumination. 

6.  Fog  is  caused  by  side-light,  or  sometimes  when  the  bright  sky  or 
the  sun  shines  into  the  objective. 

7.  Double  pictures  are  due  to  fine  holes  in  the  board  carrying  the 
objective. 

8.  Stereos  of  unequal  light  (also  single  pictures)  are  caused  by  ob- 
jectives of  unequal  light  intensity,  or  by  a  plate  which  has  been  coated 
unequally.    The  thick  spots  are  more  sensitive  than  the  thin  ones. 

7.  FAILURES  DUE  TO  DEVELOPMENT. 

1.  Bright  halo  at  the  place  where  the  developer  has  been  poured 
on.  Cause,  the  developer  has  been  poured  on  too  violently  (see  the 
chapter  on  Development  and  the  Developer). 

2.  Black  crooked  lines,  developing  streaks.  Cause,  the  developer 
has  not  been  flowed  on  evenly. 

3.  The  film  repels  the  developer.  In  this  case  the  developer  con- 
tains either  too  much  alcohol  (for  instance,  with  a  new  bath),  or  too 
little  (with  an  old  bath);  it  should  be  harmonized  either  with  alcohol 
or  a  watery  solution  of  sulphate  of  iron. 

4.  A  dark  margin  to  bright  objects  at  the  place  where  the  devel- 


148 


THE  PRACTICE  OF  PHOTOGRAPHY. 


oper  has  been  poured  on,  and  which  appears  in  the  positive  as  a 
bright  halo,  is  a  very  common  occurrence  in  developing;  it  is  due 
to  an  accumulation  of  precipitated  nitrate  of  silver  at  the  spots 
where  the  developer  accumulates.  By  changing  the  direction  of  the 
current  they  can  be  partially  avoided. 

5.  Fog  is  sometimes  caused  by  a  too  strong,  too  hot,  or  by  a  devel- 
oper containing  too  little  acid. 

6.  Most  of  the  abovementioned  phenomena  usually  manifest 
themselves  during  development,  although  they  are  not  actually  faults 
of  development. 

8.  FAILURES  IN  INTENSIFYING. 

1.  The  intensifying  solution  is  repelled  and  causes  spots  (particu- 
larly when  intensifying  with  salts  of  iron)  ;  alcohol  is  wanted. 

2.  Pale  spots  are  due  to  the  same  cause,  when  the  developer,  no 
matter  which  one,  does  not  flow  evenly  over  the  whole  plate. 

3.  A  gray  and  grainy  precipitate  is  formed  when  we  allow  the  iron 
developer  to  act  until  it  becomes  turbid. 

4.  Bluish  precipitates  in  the  shadows  are  formed  through  want  of 
acidity,  or  when  an  old  pyrogallic  solution  is  used. 

5.  Thick  spots  are  formed  by  pouring  the  developer  always  on  the 
same  spot,  particularly  when  the  intensification  is  long  continued. 

9.  FAILURES  IN  FIXING. 

1.  The  plate  looks  greenish  or  bluish  when  plates  containing  salts 
of  iron  are  fixed  with  cyanide  of  potassium  and  have  not  been  washed 
thoroughly  before  fixing. 

2.  Black  streaks,  generally  only  visible  when  looking  on  the  plate 
from  above.  Cause,  too  cold  a  fixing  solution,  or  a  too  weak  one, 
or  the  time  of  contact  has  been  too  short. 

3.  Transparent  spots  are  formed  by  a  too  strong  solution  of  cyanide 
of  potassium  which  eats  the  film  away. 

10.  FAILURE  WHICH  MANIFESTS  ITSELF  ON  DRYING  THE  PLATE. 

The  film  appears  iridescent  and  tears ;  this  happens  with  long  in- 
tensified and  short-exposed  plates.  They  may  be  saved  by  varnishing 
them  when  still  damp,  by  drying  them,  and  applying  a  second  coat  of 
varnish  warm.  It  is  still  better  to  apply  to  the  damp  film  alcohol  of 
the  strength  of  60°  and  to  varnish  afterwards. 


NEGATIVE  RETOUCHING. 


149 


11.  FAILURE  IN  VARNISHING. 

1.  The  film  dissolves,  the  picture  is  washed  away.  Cause,  the 
alcohol  in  the  varnish  is  too  strong.  Add  1  per  cent,  of  water  (see 
the  chapter  on  the  Varnish). 

2.  The  film  looks  dull.  Cause,  the  plate  was  too  cold  or  the  var- 
nish too  thin. 

3.  A  streaky  film  is  formed  when  the  plate  was  too  hot,  or  if  the 
rocking  motion  of  the  plate  when  applying  the  varnish  has  been 
uneven,  or  when  the  varnish  has  been  too  thick.  In  the  latter  case 
dilute  with  alcohol. 


NEGATIVE  KETOUCHING. 

SECTION  I. 
PRACTICAL  PART. 

The  picture  which  has  been  obtained  by  the  negative  process  is  by 
no  means  a  true  representation  of  the  object  (see  the  chapter  "  Pho- 
tography and  Truth  ").  The  contour  and  lines  are  nearly  true  if  they 
are  in  the  picture  at  all,  but  it  is  different  with  light  and  shade,  as 
will  easily  be  seen  by  taking  a  positive  from  the  negative.  Some- 
times the  result  is  very  good,  but  very  often  the  bright  lines  are  too 
bright ;  the  shadows  too  dark ;  the  slit  of  the  mouth,  the  sockets  of 
the  eye,  which  naturally  look  at  most  gray,  appear  in  the  picture 
black;  partly  this  is  due  to  underexposure,  partly  to  the  insensitive- 
ness  for  feeble  light. 

Add  to  this  the  faulty  action  of  the  colors :  yellowish  skin,  red  hair, 
affect  the  plate  like  negro  heads ;  yellow  spots  (freckles),  barely 
visible  to  the  naked  eye,  look  in  the  picture  strikingly  dark.  These 
discrepancies  have  to  be  removed ;  formerly  this  was  done  by  re- 
touching the  positive,  now  the  negative  is  retouched,  by  making  the 
spots  which  are  too  transparent  more  opaque,  either  with  color  or 
with  lead-pencil,  which  is  applied  until  the  transparent  spots  and  the 
surrounding  are  of  the  same  tone. 

It  is  obvious  that  certain  transparent  parts  like  wrinkles  may  be 
removed  entirely,  but  this  is  not  the  purpose  but  rather  a  misuse  of 
the  retouch. 


150 


THE  PRACTICE  OF  PHOTOGRAPHY. 


We  will  show  further  on  what  may  be  retouched  and  what  should 
not,  and  we  will  begin  with  the  technical  parts  according  to  Grass- 
hoff's  excellent  instructions. 

In  order  to  facilitate  the  working  of  the  negative  plates  it  is  well 
to  provide  a  stand  with  a  mirror ;  such  can  be  bought  at  the  stock- 
dealers.  The  stand  is  placed  near  the  window  in  such  a  manner  that 
the  mirror  reflects  the  sky,  the  support  carrying  the  negative  is  placed 
obliquely,  the  latter  is  screwed  firm,  and  the  negative  may  easily  and 
without  fatigue  be  examined;  Care  should  be  taken  that  the  sitter 
and  the  plate  are  as  much  as  possible  in  the  dark.  Those  who  are 
compelled  to  work  in  the  atelier,  or  in  a  room  in  which  there  are 
several  windows,  should  take  care  that  no  light  strikes  the  plate 
from  above,  otherwise  too  little  of  the  work  to  be  done  is  visible,  there- 
fore the  head  and  the  stand  should  be  covered  in  such  a  manner  that 
the  operator  sits  entirely  in  the  dark. 

Lately  stands  of  this  kind  can  be  bought  ready  made,  but  an 
arrangement  may  easily  be  made  with  pasteboard. 

If  the  retouch  has  to  be  made  at  night,  the  mirror  with  reflected 
lamplight  cannot  be  used ;  it  is  advisable  to  employ  a  lamp  with  a 
shade  of  ground-glass,  and  to  place  it  so  low  that  the  subdued  lamp- 
light strikes  the  plate  from  below  and  passes  through  it.  Besides, 
several  pieces  of  dark  paper,  according  to  the  size  of  the  plate,  should 
be  handy,  with  oval  or  round  openings  of  various  sizes,  for  covering 
the  negative  in  such  a  manner  that  only  the  head  remains  visible. 

By  such  an  arrangement  the  eye  is  less  dazzled,  as  otherwise  the 
transparent  dress,  etc.,  transmit  much  more  light,  which  disturbs  the 
worker.  The  varnish  is  also  protected,  particularly  when  the  same 
is  new. 

One  of  the  most  difficult  negative  retouches  is  a  large  portrait- 
plate,  and  it  is  particularly  the  head  which  requires  all  the  attention, 
and  I  therefore  write  in  this  sense. 

It  has  been  proposed  to  coat  the  negatives  with  gum  arabic  after 
fixing,  and  to  retouch  them  afterwards,  and  to  varnish  the  retouch. 
In  experienced  hands  the  results  are  very  good,  but  it  happens  fre- 
quently that  in  varnishing  the  varnish  penetrates  but  partially  the 
thin  film  of  gum,  and  the  negative  is  easily  lost  by  becoming  spotted. 
The  operator  has  also  to  proceed  with  the  greatest  caution  in  work- 
ing on  such  a  gum  film,  as  the  point  of  the  pencil  easily  penetrates 
the  collodion,  and  makes  holes.  For  all  these  reasons,  retouching  on 
the  varnish  is  preferable. 

The  same  applies  to  the  method  of  coating  the  negative  with  glue 
or  gelatin,  to  retouch  on  this,  and  to  varnish  afterwards. 


NEGATIVE  RETOUCHING. 


151 


A  negative  varnish  containing  much  shellac  does  not  take  lead- 
pencil  retouches  (of  which  we  speak  here  principally)  very  readily. 
I  recommend,  therefore,  the  following,  which  is  really  excellent.  The 
same  may  also  be  used  to  advantage  for  positives. 

Take— 

15  parts  absolute  alcohol,  and  dissolve  therein 
2J  parts  pulverized  sandarac, 

J  part  camphor,  crumbled, 

1  part  Venetian  turpentine, 

|  part  oil  of  lavender. 

For  use,  the  varnish  is  more  or  less  diluted  with  alcohol,  to  which, 
for  every  ten  or  twelve  parts,  about  one  part  of  distilled  water  is 
added,  or  also  some  spirits  of  wine,  as  sold  in  the  distilleries. 

It  is  preferable  to  dissolve  the  resins  in  pure  alcohol,  as  it  goes 
quicker,  and  is  more  reliable. 

The  addition  of  water  to  the  alcohol,  or  in  its  place  the  use  of 
spirits  of  wine,  is  recommended,  in  order  that  the  varnish  may  not 
destroy  the  transparent  shadows  in  the  negative. 

The  hardness  of  the  varnish  on  the  negative  increases  with  age, 
and  the  hardness  of  the  lead-pencil  should  be  regulated  accordingly. 
With  a  very  soft  varnish  a  soft  lead-pencil  should  be  used,  and  the 
hardness  should  be  increased  with  the  hardness  of  the  varnish. 
Grasshoff  used  pencils  of  A.  W.  Faber,  and  gave  the  preference  to 
those  of  Siberian  plumbago,  Nos.  1  to  4,  because  they  are  extremely 
fine,  and  actually  free  from  hard  substances.  Shortly  after  varnish- 
ing he  employed  Nos.  1  and  2 ;  after  a  few  hours  No.  2 ;  the  next 
day,  and  after  the  varnish  has  become  still  dryer,  Nos.  3  and  4  only 
should  be  used. 

The  very  smooth  and  dry  varnish  does  not  always  take  the  lead- 
pencil  lines  readily.  Grasshoff  recommends,  therefore,  cuttle-fish 
bone.  The  same  should  be  scraped  very  finely,  and  rubbed  with  the 
finger  very  carefully  over  the  negatives,  particularly  on  the  spots 
which  are  to  be  retouched — for  instance,  the  face,  or  rather  the  head 
— and  until  a  dull  surface  has  been  obtained.  The  plate  now  takes 
lead-pencil  or  India  ink  readily,  and  we  are  able  now  to  lay  on 
excellent  transitions  from  light  to  shade. 

The  varnish  film  should  not  be  too  thin,  but  rather  have  a  fine  and 
strong  surface,  and  the  more  this  is  the  case  the  less  will  it  be  possible 
to  get  small,  hair-like  cracks,  by  rubbing  it  with  cuttle-fish  bone.  In 
place  of  cuttle-fish  bone,  we  may  also  use  finely-powdered  pumice-stone. 

The  inequalities  of  the  negative — for  instance,  freckles  and  other 


152 


THE  PRACTICE  OF  PHOTOGRAPHY. 


spots  which  show  too  dark — should  be  worked  with  lead-pencil  in 
such  a  way  that  they  can  no  longer  be  distinguished  from  the  sur- 
rounding parts ;  so,  also,  large  parts  of  the  shadows  will  have  to  be 
worked  over,  and  particularly  the  sudden  transitions  from  light  to 
shade,  which  we  often  notice  in  the  negative,  will  have  to  be  equal- 
ized, in  order  to  make  the  whole  negative  more  harmonious. 

The  lead-pencil  work,  however,  does  not  suffice  always,  as  its  cov- 
ering capacity  i$  but  limited,  particularly  on  very  transparent  parts 
over  the  eyes,  with  much  top-light  illumination.  Other  parts  which 
print  too  darkly,  and  which  would  give  to  the  picture  too  heavy  and 
too  deep  a  shadow,  have  to  be  relieved,  and  here  the  best  remedy  is 
gum  arabic  and  india-ink,  which  has  been  mixed  with  water.  The 
mixture  should  have  a  syrup-like  consistence,  and  the  color  should 
have  double  the  brilliancy,  than  if  mixed  with  water  only,  and  put 
upon  paper.  It  is  also  well  to  add  to  the  gum  solution  a  few  drops  of 
glycerin — to  half  an  ounce,  about  four  or  five  drops.  The  color  works 
better,  and  does  not  rest  so  brittle  on  the  varnish.  By  varying  the 
quantity  of  the  gum,  the  covering  quality  of  the  color  may  be  pretty 
well  controlled.  If*  it  does  not  cover  sufficiently,  the  too  transparent 
spots  may  be  looked  after  for  a  second  or  third  time,  and  they  may 
be  painted,  or  rather  stippled  over,  until  sufficient  density  has  been 
obtained.  It  is  only  necessary  to  let  the  color  become  dry,  before  a 
second  coat  is  laid  on,  and  but  little  paint  should  be  taken  on  the 
brush. 

With  these  gum  colors,  whole  parts  of  the  picture  which  appear  too 
transparent  may  be  covered  so  as  to  secure  an  even  tone — for  instance, 
the  hands  or  arms,  light  dresses,  or  hair  which  has  not  been  powdered  ; 
also,  blonde  beards,  which  would  print  too  darkly ;  parts  of  uniforms 
or  costumes,  if  not  too  large.  With  a  large  and  full  brush  such  parts 
are  uniformly  covered  as  evenly  as  possible,  without  regard  to  the 
outlines,  in  order  that  the  color  may  remain  liquid.  We  breathe  on 
the  plate,  and  distribute  the  color  as  evenly  as  possible.  This  requires 
practice,  but  after  a  few  trials  it  will  not  be  difficult  to  produce  an 
even  plate.  When  the  color  has  become  dry,  those  portions  of  it 
which  overlay  the  outlines  are  removed.  This  is  done  with  a  damp 
brush. 

In  many  cases  it  is  advisable  to  apply  this  kind  of  retouch  to  the 
back  of  the  negative. 

Spots,  and  the  like,  which  still  appear  in  such  retouched  negatives, 
are  either  removed  with  lead-pencil  or  with  color. 

On  the  back  of  the  negative,  i.  e.,  on  the  glass,  some  parts  are 
thinly  covered  with  color,  in  order  to  insure  a  lighter  and  hence  more 


NEGATIVE  RETOUCHING. 


153 


correct  printing  of  objects  which  appear  too  dark  in  the  picture.  It 
is  in  this  case,  owing  to  the  thickness  of  the  glass,  not  so  necessary  to 
observe  closely  the  outlines  of  the  picture.  The  ordinary  india-ink, 
without  the  addition  of  gum  arabic,  may  be  used  also  with  advan- 
tage, as  it  covers  better. 

After  the  color  has  been  laid  on,  we  breathe  upon  the  plate,  and 
touch  it  with  the  point  of  the  finger,  until  a  uniform  grain  has  been 
secured,  for  on  the  back  of  the  picture  an  exceedingly  even  distribu- 
tion of  the  color  is  not  necessary.  If  the  density  of  the  color  is  in- 
sufficient, and  it  is  desired  to  lay  it  on  a  little  heavier,  or  only  in  some 
places  a  little  denser  color  is  required,  this  may  easily  be  done  with  a 
soft  lead-pencil,  with  which  shading  or  stippling  may  be  laid  on. 

Sap  red,  sap  blue,  Prussian  blue,  burnt  terra,  sienna,  and  gamboge, 
for  covering  or  partially  covering,  are  also  frequently  employed,  be- 
cause those  colors,  owing  to  their  transparency,  are  well  suited  for  it, 
but  with  these  colors  it  is  much  more  difficult  to  judge  of  the  density 
than  with  black,  and  by  adding  gum  arabic,  the  even  laying  on  of 
the  colors  is  made  easy,  which  otherwise  is  more  difficult  than  the 
laying  on  of  the  blue,  red,  or  yellow.  Practice  tias  much  to  do  with 
success,  and  an  experienced  hand  secures  good  results  with  any  color, 
if  it  is  understood  how  to  keep  the  right  tone. 

The  small  holes,  dots,  or  other  spots  in  the  negative  are  best  covered 
with  ordinary  india-ink,  without  the  addition  of  gum  arabic,  but 
wetting  the  point  of  the  brush  with  the  mouth  should  be  avoided,  as 
this  will  prevent  the  color  from  adhering  and  covering. 

The  negative  retouch  after  oil  painting  still  needs  mentioning ; 
negatives  of  this  kind  are  very  difficult  to  retouch.  The  different 
sensitiveness  of  the  film  for  color,  produces  sometimes  the  most  glaring 
contrasts  in  the  negative,  and  it  is  often  of  advantage  to  cover  the 
whole  plate  with  a  thin  color,  to  which  a  solution  of  gum  arabic  has 
been  added,  either  on  the  side  that  has  been  varnished,  or  also  with 
large  plates  on  the  back  or  glass  side.  The  color  is  poured  on  the 
plate,  and  flowed  over  it  very  evenly  and  left  to  dry.  On  the  places 
where  the  color  is  too  heavy,  it  is  removed  with  a  damp  cloth  or  a 
moist  brush,  etc.  The  aniline  colors  of  Dr.  Jacobsen  are  well  suited 
for  this  purpose;  they  are  to  be  had  at  the  stockdealers.  Owing 
to  their  fineness  of  grain,  they  furnish  the  desired  even  coat  of  color. 
Particularly  suited  are  green,  yellowish-brown,  and  reddish-brown.  A 
quantity  of  gum-arabic  solution,  not  too  thick,  is  taken  and  colored 
with  the  desired  tint  (in  a  wide-mouthed  bottle),  and  poured  on  the 
negative,  left  to  dry  in  a  place  free  from  dust,  and  when  dry,  the  re- 
moval of  the  places  which  are  too  dense  is  commenced  if  necessary. 


154 


THE  PRACTICE  OF  PHOTOGRAPHY. 


It  is  impossible  to  describe  this  accurately,  but  practice  will  eventually 
secure  success. 

It  may  also  happen  that  the  coating  with  color  does  not  give  good 
results,  if  a  great  many  copies  have  to  be  made,  and  all  water  colors 
are  not  insensitive  to  light  and  air.  In  this  case  another  method  is 
preferable  (particularly  with  large  surfaces  and  landscapes  taken  from 
nature),  and  that  is,  to  take  the  finest  oil-paper,  coat  it  evenly  with 
starch,  and  paste  it  to  the  glass  side  of  the  negative;  after  it  has  dried, 
those  places  which  print  correctly  should  be  cut  out  or  scraped  out. 

More  delicate  transitions  should  be  made  with  lead-pencil.  This  is 
done  to  particular  advantage  with  those  parts  of  the  negative  taken 
from  an  oil  painting,  in  which  the  lines,  ridges,  and  depressions  of 
the  paint  have  thrown  shadows,  which  in  the  original  are  not  noticed. 

Finally,  some  remarks  on  landscape  photography.  Not  always  is 
sky,  or  rather  the  air,  so  pure  and  clear  and  opaque  in  the  negative 
as  is  desirable,  and  in  this  case  it  is  necessary  to  remedy  it  with  the 
brush.  If  the  sky  is  clear  and  bright,  and  disturbs  only  because  it 
produces  a  monotonous  surface,  which  frequently  happens,  it  is  advisa- 
ble to  paint  a  few  clouds  on  to  it.  This  is  done  most  easily,  especially 
when  we  are  not  very  particular  about  the  shape,  with  india-ink,  to 
which  considerable  gum  arabic  has  been  added.  The  clouds  are 
painted  on  the  glass  side  of  the  negative  (this  need  not  to  be  done 
very  finely).  By  crossing  and  laying  the  color  on  several  times,  the 
lesser  or  greater  density  will  be  reached,  and  by  lead-pencil  draw- 
ing the  brighter  parts  will  be  produced.  Excellent  for  this  purpose 
is  black  oil  paint,  to  which  a  little  siccative  has  been  added.  This 
color  admits  of  very  even  distribution,  and  as  it  remains  moist  for  a 
long  time,  even  difficult  cloud  effects  may  be  made  with  it ;  as  a  pattern, 
a  cloud  negative  from  nature  serves  very  well.  To  print  the  clouds 
into  a  negative  by  using  two  negatives  does  not  always  give  satisfac- 
tory results,  as  frequently  such  cloud  effects  do  not  harmonize  with 
the  landscape,  and  hence  disturb.  A  change  in  the  drawing  is  easily 
made.  Although  the  thickness  of  the  glass  will  give  to  the  outlines 
already  a  rather  washed  appearance,  still  it  is  well  for  the  beginner 
to  shade  off.  Such  a  negative  can  of  course  only  be  used  after  the 
oil  paint  has  become  dry. 

Sap  red  or  blue  is  often  used  for  painting  cloud  effects ;  I,  however, 
as  stated  before,  give  the  preference  to  black. 

When  it  becomes  necessary  to  back  out  the  sky  entirely,  so  as  to 
make  the  same  appear  as  a  perfectly  white  surface,  red  is  preferable,  for 
instance,  vermilion,  English  red  or  Vandyke  red,  and  the  like.  One 
of  these  dry  colors  (black  will  also  do)  is  rubbed  very  finely  on  a 


NEGATIVE  RETOUCHING. 


155 


glass  plate,  with  a  glass  muller,  and  water,  and  to  the  thick  color  a 
little  gum  arabic  and  a  few  drops  of  glycerin  are  added.  The  color 
is  now  rubbed  for  a  second  time,  and  the  whole  syrupy  mass  is  pre- 
served in  a  suitable  vessel  for  future  use.  The  addition  of  gum  arabic 
should  be  but  trifling ;  the  color  should,  when  placed  on  paper  or  glass, 
not  rub  off.  The  addition  of  glycerin  is  to  prevent  the  splitting  and 
cracking  of  the  colors. 

The  red  color  is  preferable  because  it  covers  well,  is  easily  seen, 
and  the  outlines  can  readily  be  corrected,  and  even  if  a  spot  should 
not  be  sufficiently  covered,  the  thin  red  color  permits  less  light  to 
penetrate  than  a  thin  black  color.  Particularly  the  Vandyke  red  is 
good  for  this  purpose,  and  for  stopping  up  small  holes  in  the  negative. 

A  plain  ordinary  color  mixed  only  with  water  is  in  most  cases 
sufficient  to  back  out  the  sky;  it  is  advisable  to  add  to  such  a  color  a 
few  drops  of  glycerin. 

I  will  still  mention  that  in  place  of  the  gum  solution,  the  following 
mixture  may  be  used :  A  small  quantity  of  the  yelk  of  an  egg  is 
mixed  with  about  one-third  of  its  volume  of  oil,  and  thoroughly  stirred 
in  a  glass;  a  little  water  is  added,  and  this  compound  is  used  in  place  of 
gum  arabic  and  glycerin.  Linseed  oil,  poppy  oil,  and  sweet  oil,  are 
suitable  for  this  purpose,  but  linseed  oil  is  the  best.  This  compound 
may  be  laid  on  in  a  great  many  layers  without  dissolving  the  under- 
lying stratum,  provided  that  the  latter  has  become  sufficiently  dry. 
In  water  it  does  not  dissolve  readily,  it  should  therefore  be  kept  moist. 

The  finishing  of  the  outlines  has  to  be  done  very  carefully  when  on 
the  varnished  side ;  the  balance  of  the  picture  is  pasted  over  with  red 
paper,  cut  of  suitable  size. 

As  the  retouch  frequently  suffers  when  handled  too  much,  it  is 
advisable  to  protect  it  in  the  following  manner  :  Take  common  amber 
varnish  (the  fine  amber  varnish  dries  very  slowly  owing  to  the  large 
proportion  of  oil  it  contains),  dilute  it  with  8-10  parts  of  oil  of  tur- 
pentine, filter  well,  and  coat  the  negative  with  it  in  the  ordinary 
manner.  Let  the  negative  dry  in  a  place  free  from  dust.  On  the 
next  day,  or  later,  the  plate  is  very  carefully  retouched  with  a  soft 
lead-pencil ;  color  may  be  laid  on  in  any  suitable  way,  as  well  with 
oil  as  with  water  colors,  and  when  the  whole  of  the  retouch  has  been 
finished,  the  plate  is  warmed  a  little,  and  coated  in  the  ordinary 
manner  with  an  alcohol  negative  varnish,  and  the  latter  is  dried  with 
moderate  heat. 

Under  certain  circumstances  a  retouch  may  be  made  on  this  sur- 
face also. 


156 


THE  PRACTICE  OF  PHOTOGRAPHY. 


SECTION  II. 

THE  JESTHETICAL  PRINCIPLES  OF  THE  NEGATIVE  RETOUCH. 

We  have  already  remarked  above,  that  by  no  means  everything 
which  appears  in  the  negative  as  transparent  should  be  covered  by 
the  retouch,  and  we  will  now  cite  Hartman's  principle,  which  should 
be  gospel  to  every  retoucher. 

In  contemplating  the  human  head  and  the  formation  of  the  face, 
we  observe  that  those  parts  where  the  underlying  rigid,  bony  structure 
is  most  prominent  are  subject  to  the  least  variation.  The  surfaces  of 
the  forehead,  the  root  of  the  nose,  the  jaws,  the  margin  of  the  sockets 
of  the  eye,  always  maintain  their  relation  to  each  other. 

They  determine  the  likeness  in  conjunction  with  the  position  of  the 
slit  of  the  eye  and  the  mouth,  with  form  and  direction  of  the  nose,  and 
the  most  prominent  parts  of  the  chin.  More  or  less  contraction  of  the 
muscles,  particularly  of  the  closing  muscles  at  the  angles  of  the  eyes 
and  mouth,  give  the  expression. 

With  both  of  these  positions  of  the  face,  which  are  the  controlling 
elements  in  giving  it  its  form,  the  helping  hand  of  the  retoucher  has 
to  proceed  with  the  utmost  care.  With  regard  to  the  third  part,  the 
skin,  which  partly  gives  roundness  to  the  different  forms,  we  can  pro- 
ceed with  much  more  freedom,  particularly  where  the  hair,  accumu- 
lated fat  and  flabby  parts,  and  wrinkles  present  themselves.  We 
must  not  forget  that  the  skin,  which  forms  everywhere  the  surface, 
in  consequence  of  spots  and  impurities,  very  often  exercises  a  greater 
chemical  action  than  the  lower  forms,  which  are  generally  distin- 
guished by  a  delicate  variation  of  light  and  shade. 

To  give  due  prominence  to  the  latter,  and  to  reproduce  solely  the 
variations  of  light  and  shade,  to  exclude  the  disturbing  element  of 
color,  is  the  main  purpose  and  the  main  difficulty  in  retouching.  Let 
us  try  to  demonstrate  these  principles  in  detail,  and  to  get  them  under- 
stood. Let  us  follow  the  relation  of  the  different  parts  of  the  face,  its 
changes  in  old  age,  its  differences  in  the  sexes,  its  value  for  expression 
and  likeness. 

The  forehead,  very  round  and  soft  in  the  child,  becomes  expressive 
in  the  man,  and  divided  into  distinct  surfaces,  and  forms  a  prominent 
feature  of  the  character.  The  upper  part  of  the  forehead  shows  the 
forms  of  the  skull  the  best,  and  with  the  least  variation ;  only  the 
lower  part  of  the  forehead,  just  above  the  eyebrows,  is  enriched  with 
a  very  movable  set  of  muscles. 


PRINCIPLES  OF  THE  NEGATIVE  RETOUCH.  157 


With  suitable  illumination  the  surfaces  of  the  upper  forehead  be- 
come distinctly  separated,  and  the  care  of  the  artist  should  be  directed 
to  clearly  define  the  boundaries  of  these  surfaces,  and  to  make  them 
appear  as  a  harmonious  whole.  A  forehead  which  is  too  round  is 
admissible  in  the  female,  but  in  man  it  looks  too  feminine,  and  lacks 
beauty  here  more  than  anywhere  else.  The  defining  of  surfaces  is  in 
order. 

The  wrinkles  on  the  forehead  are  regulated  by  the  attachment  of 
the  skin  to  the  lower  part  of  the  forehead.  They  form  horizontal 
grooves  which  run  parallel  to  the  ridges  of  the  sockets  of  the  eye,  and 
finally  disappear  at  the  sides. 

As  they  make  their  appearance  in  middle-aged  persons,  and  as  they 
follow  the  forms  of  the  forehead,  we  may  let  them  remain,  and  only 
need  to  soften  them.  The  vertical  cross- wrinkles,  which  make  their 
appearance  in  advanced  age,  make  an  unpleasant  impression,  and 
should  be  removed  entirely.  Only  the  two  main  vertical  wrinkles, 
which  proceed  from  the  root  of  the  nose,  and  which  divert  the  hori- 
zontal wrinkles,  should  remain. 

The  margin  of  the  hair  at  the  temple  is  very  soft,  and  a  great 
attraction  for  the  painter.  The  eyebrows,  which  vary  greatly  in 
thickness,  color,  and  form,  have,  by  following  the  lines  of  the  sockets 
of  the  eye,  the  aesthetic  value  of  being  their  limit.  It  is  well  to  re- 
move the  hair  which  grows  too  strongly  upwards,  and  to  preserve  the 
arched  form  of  the  brow.  A  meeting  of  the  brow  above  the  nose  is 
considered  ugly.  It  gives  to  the  face  a  sinister  expression,  particu- 
larly as  in  this  place  there  is  a  shadow  already. 

The  sum  of  the  labor  of  the  retoucher  could  hence  be  expressed  as 
follows  :  Definition  of  surfaces ;  a  consecutive  separation  and  treat- 
ment of  hard  and  soft  hair  margins  ;  subduing  or  removal  of  vertical 
wrinkles,  and  a  modified  preservation  of  the  large  horizontal  wrinkles  ; 
defining  the  arch  of  the  eyebrow.  How  far  these  operations  can  be 
carried  depends  of  course  on  the  age  and  sex  of  the  original. 

The  head  seen  in  profile  very  often  shows  a  want  of  expression  in 
the  back  part.  Smallness  of  the  back  of  the  skull  in  contradistinc- 
tion to  enlarged  development  of  the  frontal  parts,  imparts  the  charac- 
teristics of  an  animal.  The  deficiency  should  be  supplied  by  retouch- 
ing, and  the  head  will  gain  in  importance.  Also,  where  the  hair  has 
been  arranged  in  an  unsymmetrical  manner,  we  can  easily  reach  the 
necessary  balance  by  adding  here  a  piece  or  deducting  something  at 
another  part.  Blonde  hair,  which  generally  takes  too  dark,  can  be 
heightened  by  laying  color  over  it,  while  in  the  more  exposed  shady 


158 


THE  PRACTICE  OF  PHOTOGRAPHY. 


parts  of  dark  hair,  the  necessary  harmony  can  be  produced  by  draw- 
ing the  necessary  details. 

Beards  and  whiskers  should  be  treated  in  a  similar  manner. 

The  Nose. — What  we  have  said  of  the  bony  structures  of  the  fore- 
head refers  also  to  the  upper  part  of  the  nose,  the  lower  part  consist- 
ing of  a  firm  muscle  which  offers  more  or  less  surface.  The  ridge  of 
the  nose  should  be  clearly  defined,  and  when  necessary  a  high  light 
should  be  placed  on  it,  to  separate  it  from  the  side  surfaces.  The 
shadows  of  the  nostrils  must  be  covered,  and  the  sides  can  be  reduced 
where  they  are  too  prominent  on  account  of  size.  Crooked  or  oblique 
noses  in  the  front  view,  very  often  admit  of  improvement.  The 
shadow  in  the  nostrils  must  not  remain  absolutely  black.  Attention 
should  also  be  given  that  the  heavy  shadow  under  the  nose  is  not  of 
the  same  depth  with  the  side  shadow ;  by  lighting  the  point  of  the 
nose  a  little  it  dissolves  itself  at  once,  and  becomes  more  plastic. 

In  a  profile  view,  it  is  not  admissible  to  alter  anything  in  the  char- 
acteristic form  of  the  ridge  of  the  nose.  The  fleshy  part,  on  the  con- 
trary, which,  with  advancing  years,  sometimes  becomes  unusually 
large,  can  be  reduced  in  size  without  any  material  detriment  to  the 
likeness. 

The  Mouth  in  its  mobility,  in  the  depression  or  elevation  of  its  cor- 
ners in  its  larger  or  lesser  expansion,  is  a  main  indicator  of  mental 
processes ;  particularly  with  children,  skilful  retouching  can  retrieve 
what  was  lost  in  the  taking  of  the  picture.  To  begin  with,  the  lips 
should  be  separated  from  the  slit  proper;  also  the  angles  should  be 
closely  defined ;  next  the  ugly  cracks  of  the  lips  should  be  entirely 
obliterated.  The  form  of  the  mouth  can  be  materially  improved  by 
clearly  defining  its  margins.  When,  with  advancing  years,  the  lines 
of  the  mouth  become  lost  in  the  wrinkles  of  the  corners,  it  is  well  to 
modify  them,  at  least  they  should  not  be  left  as  sharply  defined  as  the 
lips.  Above  the  mouth  also,  depressions  and  wrinkles  show  them- 
selves particularly  in  elderly  persons,  thus  easily  giving  the  impres- 
sion of  an  unshaved  beard.  They  should  be  removed.  But  attention 
should  be  given  to  the  different  values  of  light  and  shade  of  the  parts 
which  are  located  between  the  mouth  and  the  nose,  particularly  the 
elevated  portion  extending  from  the  dividing  line  of  the  nose  to  the 
upper  lip.  The  sharp  definitions  of  the  outer  lines  of  the  lips  is  very 
variable  in  different  individuals.  Soft  thick  lips  receive  more  light 
than  those  of  normal  form.  In  the  former  case  the  outlines  should 
not  be  too  clearly  defined,  as  this  would  give  prominence  to  a  form, 
which  is  not  warranted  by  its  light  effect.  The  angles  of  the  mouth 
may  be  modified,  and  in  the  heads  of  elderly  persons,  reduced  in-size, 


PRINCIPLES  OF  THE  NEGATIVE  RETOUCH.  159 


but  should  never  be  entirely  obliterated;  this  modification  can  be 
made  stronger  in  the  lower  than  in  the  upper  lip,  for  when  the  corners 
of  the  mouth  are  drooping,  they  indicate  weakness,  sorrow,  or  other 
unfavorable  expressions. 

Teeth,  generally,  are  much  shaded ;  to  obliterate  them  completely 
by  removing  the  opening  between  the  lips  is  sometimes  desirable,  ex- 
cept where  the  opening  is  considerable,  when  the  lips  would  become 
too  large. 

The  eye  is  of  so  much  importance  as  one  of  the  most  prominent 
parts  of  the  face  that  already,  during  the  sitting,  the  principal  atten- 
tion of  the  photographer  is  given  to  its  direction,  its  expression  and 
its  surroundings.  Notwithstanding  all  this  there  is  plenty  left  for  the 
helping  hand  of  the  retoucher.  I  will  mention  a  few  instances.  The 
clear  and  steady  expression  at  the  beginning  of  the  sitting  becomes 
disturbed,  the  lids  and  eyeballs  sink  almost  imperceptibly,  and  the 
high-lights  in  the  upper  part  of  the  latter  become  indistinct,  or  are 
entirely  covered  by  the  lashes.  It  is  easy  to  improve  here ;  the  edges 
of  the  iris  should  be  sharply  circumscribed  in  the  negative,  and  the 
high-lights  should  be  covered.  It  frequently  happens  that  the  high- 
lights in  the  eye,  on  the  shady  side  of  the  picture,  are  stronger  than 
those  of  the  illuminated  side ;  it  is  self-evident  that  a  medium  effect 
must  be  produced  here.  In  a  similar  manner  the  lower  lids  frequently 
lack  sharpness  on  account  of  the  repeated  shutting  of  the  eyes.  On 
the  edge  of  the  lids  we  generally  find  a  sharply  defined  and  very  promi- 
nent light,  generally  brighter  than  the  tone  of  the  white  in  the  eye ; 
this  light  is  easily  defined  and  intensified.  Through  the  white  of  the 
eye  we  frequently  find,  and  this  is  particularly  the  case  with  aged 
persons,  numerous  small  arteries  intersecting  it,  which  in  the  photo- 
graph give  a  motley  and  spotted  appearance.  These  can  be  removed 
entirely,  only  attention  should  be  given  that  the  white  does  not  become 
too  bright. 

Regarding  the  surroundings  of  the  eye,  the  fleshy  part  above  it  is 
apt  to  appear  too  dark,  and  become  unpleasant.  The  aim  should  be 
to  lighten  them  and  the  eyebrows,  also  the  wrinkles  above  the  eye, 
and  the  photographic  gradation  of  tone  should  be  made  to  correspond 
as  nearly  as  possible  with  the  natural  ones.  The  so-called  tear-bags 
under  the  eye  generally  throw  a  shade  which  looks  too  dark  in  the 
picture.  The  wrinkles,  which  in  aged  persons  almost  invariably  make 
their  appearance  here,  may,  in  a  modified  form,  and  in  their  horizontal 
direction,  be  maintained,  only  the  lines  running  crossways,  which 
always  give  an  irritating  effect,  should  be  obliterated ;  this  gives  clear- 
ness to  the  lines  which  run  parallel  with  the  lower  margin  of  the  eye, 


160 


THE  PRACTICE  OF  PHOTOGRAPHY. 


and  which  in  their  inner  end  point  towards  the  angle  of  the  eye. 
Immediately  adjoining  the  lower  of  these  lines  is  the  flesh  of  the 
upper  cheek,  which  firmly  rests  on  the  bone  ridge  which  forms  the 
socket  of  the  eye,  and  which  in  its  almost  invariably  recurring  arched 
form,  should  be  preserved,  collecting  the  light  on  it.  A  shadow  ex- 
tending under  the  eye  downwards  is  either  a  consequence  of  a  darker 
color,  or  of  a  deficiency  in  flesh,  which  gives  to  the  face  a  neglected 
and  sorrowful  aspect.  When  this  is  not  very  prominent  it  can  be  re- 
moved entirely,  otherwise  it  can  be  modified  to  a  considerable  degree. 
The  wrinkles  in  the  corners  of  the  eyes,  the  so-called  crow  feet,  are 
too  characteristic  and  should  not  be  obliterated  entirely. 

The  Cheeks  are,  in  their  outlines  and  surfaces,  determined  by  the 
prominence  of  the  cheek-bones.  A  certain  view  will  bury  the  cheek- 
bone in  its  profile,  and  will  give  it  too  much  prominence.  This  want 
of  beauty,  which  is  peculiar  to  the  Mongolian  race,  is  easily  remedied 
by  cutting  off  the  too  prominent  curve  of  the  bone.  As  to  the  surface 
formation  of  the  cheeks  care  should  be  taken  for  a  gentle,  but  at  the 
same  time  determined,  separation  of  the  front  and  side  parts,  to  avoid 
the  shadows  which  indicate  excessive  thinness.  Where  exposure  to 
the  weather  has  darkened  the  cheeks,  as  is  the  case  with  soldiers,  or 
people  who  lead  an  outdoor  life,  the  surfaces  should  be  covered  on  the 
back  of  the  negative. 

The  Chin  is,  in  old  and  fleshy  persons,  generally  provided  with  a 
cushion  of  fat,  which  extending  downwards  covers  a  large  portion  of 
the  throat  in  a  manner  by  no  means  beautiful,  and  by  giving  too 
much  breadth  to  the  lower  part  of  the  face  causes  ugly  proportions  of 
the  head.  As  we  have  already  remarked  above,  collections  of  fat, 
being  merely  external,  are  the  parts  of  the  face  most  accessible  to 
retouch. 

In  profile  views  parts  can  be  cut  off.  In  full  face  views,  by  remov- 
ing the  lower  folds,  a  part  of  the  so-called  double  chin  can  be  united 
with  the  throat,  and  the  side  has  to  be  changed  correspondingly. 

The  dimple  in  the  centre  of  the  chin  has  to  be  modified,  as  it  often 
takes  the  form  of  a  cut,  or  a  dark  tint. 

The  Neck. — What  we  have  said  above  in  regard  to  the  chin,  refers 
almost  with  equal  force  to  the  neck.  Where  the  neck  is  thin,  the 
artist  will  do  well  to  cover  the  shadows  which  are  produced  by  veins, 
arteries,  sinews,  etc.,  and  by  corresponding  additions  or  diminutions  to 
bring  about  a  form.  The  .same  may  be  said  of  the  shoulders,  the 
bosom,  the  arms,  waist,  and  hands.  Of  course  we  can  proceed  here 
with  more  freedom,  as  the  parts  mentioned  have  not  the  same  value 
in  producing  the  likeness  as  the  different  parts  of  the  face.  Angular 


PRINCIPLES  OP  THE  NEGATIVE  RETOUCH.  161 


and  thin  shoulders,  thin  arms,  a  deficient  bosom,  and  all  the  shoals 
threatening  female  beauty,  the  painter  should  avoid  under  all  circum- 
stances, and  the  photographer  may  do  likewise  whenever  his  taste 
and  his  knowledge  of  the  normal  form  permit  him  to  do  so.  This 
refers  also  to  crooked  outlines  of  the  hair,  to  the  removal  of  folds  in 
ladies'  ill-fitting  dresses,  as  they  appear  so  often  in  the  sleeves,  or  on 
the  shoulders  ;  likewise  in  the  pantaloons  of  gentlemen. 

It  is  certainly  a  circumstance  in  favor  of  retouch,  and  particularly 
of  the  negative  retouch,  that  by  skilful  manipulation  a  number  of 
shortcomings  may  be  avoided,  which  by  arrangement,  position  of  the 
original,  and  all  kinds  of  experiments,  can  only  partially  be  overcome, 
and  which  would  give  the  parties  concerned  a  great  deal  of  trouble. 


11 


162 


THE  PRACTICE  OF  PHOTOGRAPHY. 


CHAPTER  V. 

THE  POSITIVE  OR  SILVER  PRINTING  PROCESS. 

The  pictures  which  are  taken  with  the  camera  obscura  are  on 
glass ;  when  we  look  at  them  by  holding  them  to  the  light  they  ap- 
pear negative,  while  by  reflected  light  and  with  a  dark  background 
they  appear  positive. 

The  silver  which  covers  the  high  lights  appears  by  reflected  light 
grayish-white  or  bright,  while  the  uncovered  transparent  shadows 
show  the  dark  background  and  appear  dark,  hence  the  whole  picture 
appears  positive. 

On  account  of  the  heavy  deposit  of  silver  on  our  negatives  the  finer 
details  are  not  visible  in  the  lights.  When,  however,  the  exposure 
has  been  short,  and  no  intensification  has  been  resorted  to,  we  will  get 
a  picture  with  good  details,  which  in  America  is  called  an  "  ambro- 
type." 

These  ambrotypes  were  much  in  vogue  in  the  early  days  of  the  col- 
lodion process.  The  gray  color,  however,  the  reversion  of  right  and 
left,  and  their  liability  to  become  broken,  brought  them  soon  into  dis- 
favor, and  the  public  gave  the  preference  to  paper  pictures,  which  are 
made  by  placing  a  sensitive  paper  under  a  negative  and  exposing  it 
to  light. 

The  operations  necessary  for  this  purpose  are  called  the  printing  or 
positive  process. 

There  are  two  kinds  of  printing  processes : 

1.  The  direct  printing  process,  where  the  exposure  to  light  is  con- 
tinued until  the  print  has  reached  the  desired  intensity. 

2.  The  indirect  printing  process,  or  printing  by  development,  where 
the  paper  is  illuminated  for  only  a  short  time,  and  the  picture  is  after- 
wards brought  up  to  the  necessary  intensity  by  development.  This 
latter  process  is  analogous  to  making  a  negative,  and  can  also  be  em- 
ployed in  making  transparent  positives  on  glass. 

The  direct  printing  process  is  the  one  which  is  generally  practiced. 

From  drawings,  direct  copies  can  be  taken  by  the  aid  of  the  aniline 
process.  Pictures  can  be  made  in  gold,  silver,  and  pigments ;  the 
negative  can  be  reproduced  on  stone  and  metal,  and  prints  can  be 
taken  from  the  latter. 


THE  POSITIVE  OR  SILVER  PRINTING   PROCESS.  163 

Generally,  we  understand,  when  speaking  of  a  photographic  print- 
ing process,  a  method  of  producing  a  picture  by  the  direct  action  of 
light  on  a  sensitive  piece  of  paper.  I  may  mention  also  the  produc- 
tion of  silver,  iron,  or  uranium  pictures,  and  the  pigment  or  carbon 
pictures. 

Of  all  the  different  printing  processes  only  one  has  firmly  taken 
hold  in  practice ;  it  is  the  silver  printing  process,  or  the  production  of 
a  picture  on  paper  which  has  been  treated  with  a  solution  of  the  salts 
of  silver. 

Of  all  the  different  processes  it  is  the  easiest  to  manage,  yields  with 
the  simplest  means  the  most  brilliant  effects,  and  would  be  perfect  if 
the  results  were  permanent,  or  if  the  gases  containing  sulphur  would 
not  affect  the  silver  prints  in  a  similar  manner  in  which  these  gases 
affect  metallic  silver,  by  turning  it  into  a  sulphate,  which  makes  them 
look  yellow. 

Lately  the  carbon  printing  process,  on  account  of  the  permanence 
of  its  results,  has  been  employed  for  the  production  of  pictures  where 
permanence  is  the  main  object. 

If  a  sensitive  paper  which  is  darkened  by  light  is  covered  with  a 
negative,  the  light  passes  through  all  the  transparent  parts  of  the 
negative  and  blackens  the  paper,  but  under  the  dense  parts  of  the 
negative  the  paper  remains  white.  The  result  is  a  picture  which  is 
the  contrary  of  the  negative,  i.  e.,  a  positive  "  print."  To  get  a  sharp 
picture  in  this  manner,  the  paper  must  be  in  intimate  contact  with  the 
negative  ;  both  are  pressed  together. 

The  machinery  which  is  necessary  for  that  purpose  is  of  a  very 
simple  character. 

The  negative  is  ready ;  it  is  necessary  to  bring  the  same  in  close 
contact  with  the  sensitive  paper,  and  to  expose  it  to  light.  The  light 
passes  through  the  negative  from  all  sides  ;  a  print  can  only  reproduce 
itself  as  a  print,  when  the  distance  between  the  paper  and  the  nega- 
tive film  is  equal  to  0.  When  the  distance  is  greater  the  print  will 
appear  as  a  diffused  circle  of  light.  The  picture  will  not  be  sharp. 
To  secure  this  intimate  contact,  presses  called  printing-frames,  are 
used,  and  this  has  given  to  the  process  the  general  name  of  printing 
process. 

The  printing-frames  consist  of  a  wooden  square  a  a,  in  which  a 
piece  of  plate-glass  has  been  inserted,  and  a  cover  D,  which  is  di- 
vided in  the  centre  and  supplied  with  hinges.  This  cover  is  pressed 
against  the  negatives  by  the  springs  attached  to  the  crossbars,  e  e 
(see  Figs.  67  and  68),  or  ff  in  the  frame  for  large  prints,  Fig.  69. 


164 


THE  PRACTICE  OP  PHOTOGRAPHY. 


The  negative  is  first  placed  into  the  frame  with  the  film  upwards ; 
on  this  the  sensitive  paper  is  placed ;  a  piece  of  felt  or  a  paper  cush- 


Fig.  67. 


Fig 


ion  is  laid  on  top  of  it ;  next  comes  the  cover,  D ;  and  the  whole  is 
held  in  place  by  the  springs  and  crossbars,  e  e. 


Fig. 


In  place  of  the  springs,  wedges  are  sometimes  used ;  these  are  less 
liable  to  breakage. 

For  small  plates,  such  as  carte  de  visite  negatives,  the  plate-glass 
can  be  dispensed  with.  This  is  of  advantage,  for  it  will  always  ab- 
sorb some  light.  Meagher,  in  England,  has  constructed  printing- 
frames  in  which  the  negative  rests  on  bands  of  india-rubber.  This 
prevents  the  breakage  of  negatives  which  are  slightly  curved, — a  cir- 
cumstance that  frequently  takes  place  when  the  negative  is  placed  on 
plate-glass. 


PREPARATIONS  —  THE  PAPER. 


165 


SECTION  I. 
PREPARATIONS. 

I.  The  Paper. 

In  the  negative  process  the  collodion  is  the  most  important  carrier 
of  the  picture;  in  the  positive  process  it  is  the  paper,  of  which  we  will 
give  a  description  after  noticing  all  the  material  necessary  to  its  pro- 
duction. The  sketcher  uses  for  his  designs  a  firm,  smooth,  homogene- 
ous paper ;  this  is  also  necessary  in  photography.  On  Swedish  filter- 
ing-paper, for  instance,  we  would  obtain  rough  and  fibrous  pictures  ; 
besides  this,  the  paper  being  soft  and  hard  in  spots,  an  uneven  absorp- 
tion of  the  sensitizing  solution  would  cause  an  uneven  darkening  when 
exposed  to  the  light.  Further,  the  chemicals  would  sink  into  a  por- 
ous or  fibrous  paper  correspondingly,  a  part  of  the  picture  would  be 
formed  in  the  paper  and  be  visible  by  transmitted  light  (like  a  nega- 
tive) instead  of  reflected  light.  Besides  this,  such  a  paper  would  be 
very  insensitive,  and  would  be  apt  to  tear  in  the  washing.  From  the 
above  intimations,  it  can  already  be  seen  what  qualities  a  photo- 
graphic paper  must  possess. 

1.  It  must  form  a  perfectly  smooth,  firm,  and  homogeneous  stratum. 

2.  It  must  not  allow  the  sinking  in  of  the  chemicals,  but  keep  them 
fast  on  the  surface. 

3.  It  must  color  quickly  and  even,  when  exposed  to  the  light,  at 
the  same  time  assuming  a  brilliant  and  pleasing  tone. 

The  first  requirement  is  met  with  a  careful  selection  of  the  raw 
material.  Only  the  best  linen  rags  should  be  used.  In  the  manu- 
facture all  iron  utensils  should  be  avoided  if  possible ;  they  are  the 
cause  of  rust-spots,  which  show  black  iron  spots  in  printing.  There 
are  very  few  paper  factories  in  existence  which  furnish  a  sterling 
paper  for  photographic  purposes.  There  are  really  only  two  known, 
one  in  Rive  near  Paris,  the  other  Steinbach's  in  Malmedy.  These  fur- 
nish almost  all  the  enormous  quantity  which  is  daily  used  in  pho- 
tography. As  remarked  above,  the  paper  furnished  by  these  is  the 
so-called  raw  paper,  which  must  receive  a  supplementary  sizing  and 
salting  to  make  it  serviceable  for  photographic  purposes.  By  this 
sizing  the  second  requirement  is  fulfilled  (see  above).  The  sizing 
forms  a  protective  covering,  fills  the  pores  of  the  paper,  makes  a  homo- 
geneous surface,  increases  the  firmness  and  sensitiveness.    The  raw 


/ 


166  THE  PRACTICE  OF  PHOTOGRAPHY. 

paper  is  not,  however,  unsized,  but  has  already  received  a  sizing  in 
the  factory,  either  of  gelatin  and  alum,  or  alum  and  resin  soap.  This 
sizing  is  generally  a  secret  of  the  manufacturer,  in  consequence  of 
which  certain  papers  have  gained  a  good  reputation.  The  method  of 
the  sizing  has  an  influence  on  the  tone  of  the  finished  picture,  therefore, 
little  differences  in  the  sizing  have  great  effects  in  the  appearance  of 
the  picture.  The  first  sizing  which  the  paper  receives  in  the  factory 
will  suit  for  pictures  of  subordinate  quality,  but  to  obtain  brilliant 
copies,  the  paper  is  covered  with  different  substances,  which  besides 
requirement  2  (see  above)  fill  requirement  3.  For  such  purposes 
albumen,  starch,  and  resin,  seldom  gelatin,  and  lately  collodion  have 
been  used.  Of  the  above  substances,  the  first  is  mostly  used.  The 
albumen  covering  commends  itself  by  its  great  sensitiveness  to  light, 
the  intense,  brilliant  appearance  it  assumes  in  printing,  pretty  tone 
and  gloss,  and  great  sharpness  of  detail  of  pictures  printed  on  it.  It 
is,  however,  hard  to  retouch  upon.  The  second  substance  is  starch, 
which  forms  a  covering  of  dim  lustre,  and  produces  inferior  pictures 
of  a  dull  tone,  which,  however,  are  easily  retouched.  The  resin  is 
seldom  used,  the  quality  being  similar  to  the  starch.  According  to 
these  coverings  the  photographic  paper  is  divided  into  albumen, 
arrowroot,  and  resin  paper.  The  first  is  used  the  most,  the  second  is 
only  used  for  large  colored  or  retouched  pictures,  the  third  has  as  yet 
received  no  common  application.  To  prepare  the  first,  the  white  of 
chicken-eggs  is  used,  which  represents  more  or  less  pure  albumen 
and  fibrin  solution.  The  simplest  process  to  make  albumen  paper  is 
as  follows  :  Separate  the  yolks  from  the  whites ;  to  8  parts  of  the 
whites,  2  parts  of  a  solution  of  10  parts  of  chloride  of  ammonium  in 
100  parts  of  water,  beat  it  to  froth  (or  shake  it),  leave  stand  a  few 
hours.  The  fibrin  contained  in  the  white  is  separated,  which  would 
make  bronze-looking  stripes.  Pour  the  beaten  and  settled  albumen  in 
a  flat  dish,  lay  the  raw  paper  with  the  sized  side  upon  it,  let  it  re- 
main one  and  a  half  minutes,  pick  it  up  carefully,  leave  drain,  then 
dry.    Should  any  bubbles  appear  the  operation  must  be  repeated. 

Hardwich  recommends  the  following  proportions :  15  ounces  white 
of  egg,  5  ounces  water,  200  grains  chloride  of  ammonium.  One  sheet 
of  paper  will  take  up  from  this  bath,  according  to  Hardwich,  6  drachms 
of  albumen  and  7  grains  of  salt.  Lately,  the  quantity  of  salt  added 
has  been  reduced  1-1J  parts,  to  100  parts  of  albumen  solution,  the 
weak  salted  papers  printing  better  under  thin  negatives.  The  water 
acts  an  important  part  in  connection  with  the  albumen,  thick 
albumen  producing  a  glossy  surface  and  brilliant  prints,  therefore 
the  thickly  albumenized  paper  is  called  brilliant  albumen  paper. 


PREPARATIONS 


— THE  PAPER. 


167 


The  main  difficulty  consists  in  avoiding  streaks,  which  would  appear 
bronzed  afterwards.  To  prevent  this,  the  paper  is  laid  on  with  a  con- 
tinued proportionate  movement.  Many  papers  are  moistened  very 
slowly  by  albumen ;  this  is  caused  by  greasiness  ;  then  add  (according 
to  Hardwich)  2  parts  of  spirits  of  wine  (thinned)  to  32  parts  of  albu- 
men, or  a  few  drops  of  a  solution  of  oxgall  in  alcohol.  The  paper 
must  not  be  moistened  on  the  back,  and  not  float  too  long,  or  the 
albumen  will  sink  in  (by  dissolving  the  sizing),  and  produce  weak 
pictures.  The  more  water  is  added  to  the  albumen,  the  duller  is  the 
appearance  of  the  paper  prepared  ;  in  this  case,  however,  the  sizing  of 
the  raw  paper  has  a  great  influence  thereon.  After  removing  from 
the  dish,  the  sheet  is  hung  up  with  two  pins,  the  surplus  albumen  is 
allowed  to  run  off,  then  place  the  sheet  in  a  warm  place,  previously 
fastening  all  corners.  Finally  press  the  sheets  and  keep  them  in  a 
middling  cool  place. 

To  prepare  the  arrowroot  paper,  take  100  water,  and  2  to  3  NaCl ; 
heat  the  filtered  solution  to  the  boiling-point ;  add  3J  parts  of  pow- 
dered arrowroot ;  stir  constantly ;  pour  through  a  towel ;  spread 
the  mixture  over  the  paper  by  means  of  a  flat  brush  to  and  fro; 
finish  with  a  second,  then  dry.  Space  will  not  permit  to  speak  of  the 
technicalities  of  the  manufacture  of  arrowroot  and  albumen  paper, 
the  less  so,  as  this  branch  is  very  seldom  practiced  by  photographers, 
but  by  regular  establishments  for  that  purpose.  We  have,  however,  to 
speak  of  the  part  which  the  quantity  of  salt  contained  in  the  paper 
acts  in  photographic  practice.  It  is  manifest,  that  when  a  salted 
sheet,  i.  e.,  paper  containing  metallic  chloride,  is  placed  on  a  nitrate 
of  silver  bath,  chloride  of  silver  is  formed  in  the  paper ;  besides  this  a 
certain  quantity  of  the  silver  is  absorbed  mechanically  by  the  paper, 
thereby  containing  often  chloride  and  nitrate  of  silver.  To  judge  of 
the  effects  of  these  two  substances,  the  effect  of  each  must  be  studied. 
If  these  sheets  are  exposed  (one  containing  only  nitrate  of  silver,  the 
other  only  chloride  of  silver,  and  the  third  both  salts)  to  the  light  it 
will  be  observed  the  first  will  darken  very  slow,  coloring  brown,  the 
second  color  faster,  coloring  violet,  the  third  very  intense  and  quickly. 
The  nitrate  of  silver  by  itself  is  too  insensitive,  chloride  of  silver  con- 
siderably more  so,  but  does  not  give  intensity  of  coloring ;  only  by 
co-operation  of  the  two  substances  pictures  of  good  intensity  are  ob- 
tained. The  cause  is  this  :  chlorine,  which  is  set  free  from  the  chloride 
of  silver  by  exposure,  acts  on  the  free  nitrate,  changing  it  to  chloride, 
which  is  again  changed  while  exposed  to  the  light,  setting  free  its 
chlorine,  etc.,  etc.  In  this  manner  the  sensitive  material,  i.  e.,  chloride 
of  silver,  is  formed  continually  during  the  exposure.  If  the  free  nitrate 


168 


THE  PRACTICE  OF  PHOTOGRAPHY. 


of  silver  forms  a  chemical  combination  with  the  paper  material,  as  is 
the  case  with  albumen  paper,  the  relation  is  somewhat  different.  Here 
silver  albuminate  is  formed,  which,  in  the  pure  state,  i.  e.,  free  from 
chloride  of  silver,  is  sensitive  to  light,  nevertheless  the  salted  albumen 
paper  is  preferred. 

II.  The  Positive  Silver  Bath. 

For  the  sensitizing  of  the  picture-bearing  material  a  solution  of 
silver,  the  positive  bath,  is  used,  similar  to  that  in  the  negative  pro- 
cess. 

The  strength  of  the  latter  was  formerly  taken  very  high,  1  part  of 
nitrate  of  silver  to  4 — 5  parts  of  water.  Kecently,  however,  weaker 
solutions  have  been  employed.  We  take  now  1  part  of  nitrate  of 
silver  to  8 — 10  parts  of  water.  To  take  still  more  diluted  solutions  is 
not  advisable.  Some  kinds  of  albumen  paper  are  only  imperfectly 
coagulated  by  diluted  silver  solutions;  1  part  of  the  organic  substance 
is  dissolved  in  the  bath,  and  imparts  to  it  a  brown  color,  and  makes 
it  useless. 

Even  in  concentrated  solutions,  as  1 — 8  or  1 — 10,  this  sometimes 
happens. 

In  such  cases  the  bath  should  be  strengthened.  Alkaline  baths  are 
more  apt  to  turn  brown  than  acid  ones,  and  a  remedy  recommends 
itself,  i.  e.,  to  make  the  bath  acid  by  the  addition  of  a  few  drops  of 
nitric  acid.    Papers  that  work  well  do  not  require  this. 

Other  additions  to  the  silver  bath,  as  citric  acid,  tartaric  acid,  etc., 
are  superfluous. 

The  question  whether  strong  or  weak  silver  baths  are  preferable 
was  much  discussed  a  few  years  ago. 

At  first  sight  it  would  appear  as  if  a  weak  bath  would  be  more 
economical,  but  in  many  respects  this  is  an  error.  Every  sheet  of 
albumen  paper,  no  matter  whether  it  is  placed  on  a  strong  or  a  weak 
bath,  absorbs  a  certain  quantity  of  silver,  which  is  equivalent  to  the 
amount  of  salt  it  contains,  and  which  is  transformed  into  chloride  of 
silver ;  another  part  forms  an  albuminate  of  silver,  and  still  another 
is  absorbed  mechanically.  It  is  probable  that  the  last-named  quan- 
tity is  smaller  with  a  weak  than  with  a  strong  bath  (an  analysis  on 
this  point  is  not  at  hand). 

It  is,  however,  a  question  whether  the  employment  of  a  weak  bath 
is  advisable  for  the  sake  of  this  problematical  saving. 

A  weak  bath  is  soon  exhausted  ;  it  becomes  poorer  with  every  sheet 
floated,  and  soon  the  amount  of  silver  will  be  reduced  to  a  point  where 


PREPARATIONS  —  THE  POSITIVE  SILVER  BATH.  169 


it  is  no  longer  sufficient  for  sensitizing,  and  weak  and  dull  pictures 
will  be  the  result. 

A  strong  bath  loses  also  by  being  used,  but  not  nearly  in  the  same 
proportion  as  a  weak  one.  It  can  be  used  almost  to  the  last  drop 
without  serious  inconvenience. 

A  weak  bath  necessitates  long  sensitizing ;  a  strong  bath  sensitizes 
rapidly  and  furnishes  sheets  which,  particularly  in  dull  weather,  will 
print  much  more  brilliant  than  those  which  have  been  floated  on  a 
weak  solution. 

Any  one  who  desires  to  work  with  a  weak  bath  should  take  notice 
of  what  has  been  said  above ;  from  time  to  time  he  should  test  the 
strength  of  the  bath  (see  below  the  test  for  nitrate  of  silver),  and 
fresh  nitrate  should  be  added  frequently  to  maintain  the  standard. 

Strong  baths  do  not  require  this  care. 

The  cousumption  of  silver  in  the  positive  process  is  of  particular 
interest.  This  depends  on  different  factors ;  partly  on  the  amount  of 
salt,  partly  on  the  thickness  of  the  albumen  film ;  sometimes  the 
length  of  floating  exercises  an  influence ;  finally,  the  more  or  less 
rapid  removal  of  the  paper  from  the  bath,  and  the  strength  of  the 
latter,  have  to  be  taken  into  account. 

It  is  no  wonder  then  that  the  consumption  of  silver  is  stated  so  dif- 
ferently by  different  observers. 

Davaune  and  Girard  state  the  amount  at  3.76  grains  per  sheet  of 
17  x  22  inches.  Spiller  states  3  grains,  and  Hardwich  states  not 
quite  2  grammes. 

As  these  reports  differ  so  widely,  Mr.  Meicke  made  a  number  of 
experiments,  in  the  Berlin  Academy,  to  determine  the  consumption 
of  silver. 

500  cubic  centimetres  of  silver  bath  of  the  strength  of  1  :  8  were 
made,  and  from  20  to  25  sheets  were  floated  on  it ;  the  bath  was 
tested  by  Vogel's  method  for  the  loss  of  silver. 

The  remnant  of  the  bath  was  again  increased  to  500  centimetres, 
and  restored  to  the  strength  of  1:8,  and  from  20  to  25  sheets  were 
floated  on  it. 

In  this  manner  the  bath  was  strengthened  five  times  in  succession, 
and  used  over  again. 
The  result  was, 

From  the  fresh  bath  a  sheet  consumed  2.61  grammes. 

"  "  once  strengthened  bath  a  sheet  consumed  2.46  " 
"     "  twice  "  "        "  "        2.38  " 

"  thrice         "  "        "  "  2.00 

"     "  four  times   "  "        "  "  2.17 


170 


THE  PRACTICE  OF  PHOTOGRAPHY. 


We  deduce  from  this  the  curious  result  that  the  consumption  of  silver 
is  less  in  an  old  and  strengthened  bath  than  in  a  new  one  containing 
the  same  amount  of  silver,  and  that  the  absorption  of  silver  decreases 
with  repeated  strengthening. 

The  cause  of  this  may  be  sought  in  the  fact  that  the  combination 
of  the  alkali  with  nitric  acid  increases  with  every  sheet,  and  exercises 
a  peculiar  influence  on  the  absorption  of  silver. 

The  average  consumption  is  2.4  grammes  of  silver  per  sheet  of 
paper. 

In  the  atelier  of  Hirsh  Nickel,  perhaps  the  largest  establishment  in 
Germany  for  reproductions,  the  average  amount  of  silver  consumed 
per  sheet  is  equal  to  T*¥  of  an  ounce,  or  2.38  grammes. 

Lately  the  sheets  being  salted  weaker,  the  consumption  is  still 
less.  Schaarwachter  estimates  the  consumption  per  sheet  to  be  1  to  2 
grammes,  equal  to  20  grains. 

III.  The  Toning  Bath. 

The  printed  picture  has  an  agreeable  violet  color ;  it  would,  how- 
ever, soon  disappear  when  exposed  to  the  light,  as  the  darkening  of 
the  salts  of  silver  would  continue,  and  turn  the  whole  sheet  into  a 
homogeneous  black.  To  make  it  permanent  the  unaffected  salts  of 
silver  have  to  be  removed  by  a  fixing  agent,  such  as  hyposulphite  of 
soda. 

This  imparts  to  the  pictures  an  ugly  yellow  color.  To  obviate  this, 
the  prints  are  treated  with  a  solution  of  gold.    They  are  toned. 

The  reduced  silver  of  the  picture  acts  on  the  solution  of  gold  ;  chlo- 
ride of  silver  is  formed,  and  metallic  gold  takes  the  place  of  the 
silver. 

The  silver  picture  is  partially  changed  into  a  gold  picture,  and  the 
more  completely  so,  the  longer  the  action  is  continued.  This  has  a 
great  influence  on  the  color  of  the  picture ;  when  it  has  been  toned 
for  a  short  time,  the  color  is  brownish ;  longer  toning  imparts  to  it  a 
bluish  or  slaty  tint.  The  color  of  these  toned  pictures  is  but  little 
affected  by  the  fixing  bath.  The  toning  process  makes  the  pictures 
not  only  more  beautiful,  but  also  more  durable.  Gold  is  much  less 
subject  to  atmospheric  influences  than  silver,  and  a  toned  picture  re- 
sists the  action  of  the  atmosphere  much  better  than  an  untoned  one. 

Next  to  the  duration  of  the  toning  process,  the  reaction  of  the  gold 
bath  exercises  a  marked  influence  on  the  color  of  the  picture.  An 
acid  gold  solution  imparts  to  the  pictures  a  brownish  color ;  a  neutral 
solution  produces  a  violet  tint ;  and  when  the  bath  is  alkaline,  the  re- 
sulting picture  will  be  a  bluish  violet.   Which  color  is  the  handsomest 


PREPARATIONS — THE  TONING  BATH. 


171 


or  the  most  suitable  is  purely  a  matter  of  taste,  and  we  find  baths  of 
very  different  reactions  in  common  use.  The  one  recommends  this, 
the  next  recommends  something  else. 

An  important  point  further  is  the  concentration  of  the  bath.  A 
strong  bath  acts  so  energetically  on  the  prints,  the  color  changes  so 
rapidly  from  brown  to  blue,  that  it  is  scarcely  possible  to  watch  the 
changes.  With  a  strong  bath,  irregular  precipitates  are  apt  to  form 
in  consequence  of  the  influence  of  reducing  organic  substances.  It  is 
well  to  employ  very  diluted  gold  solutions,  particularly  when  these 
precipitates  commence  to  show  themselves.  Generally  it  is  well  to 
take  1  part  of  gold  to  from  1000  to  2000  parts  of  water. 

Gold  is  a  metal  which  is  very  easily  reduced  from  its  solutions. 
The  action  of  light  alone  is  sufficient  to  precipitate  brown  or  red 
powdered  gold  from  a  gold  solution.  When  the  water  contains  only 
a  minute  quantity  of  organic  matter — and  that  is  generally  the  case 
— the  reduction  will  take  place  even  in  the  dark.  It  is  no  wonder 
that  the  diluted  solutions  of  gold,  which  we  employ  in  the  form  of 
toning  baths,  suffer  decomposition  so  rapidly,  although  we  ascribe  to 
the  acid  toning  bath  an  unlimited  usefulness. 

The  fact  is  the  latter  are  the  most  permanent,  the  neutral  ones  are 
less  so,  and  the  alkaline  the  least. 

The  latter  sometimes  lose,  in  an  hour  after  toning,  their  yellow  color 
and  their  usefulness. 

According  to  the  investigations  of  Davanne  and  Girard,  this  is  ex- 
plained by  a  peculiar  action  of  the  alkalies. 

When  a  gold  solution  is  mixed  with  an  alkali,  or  a  salt  of  an  alka- 
line reaction,  a  mixture  will  be  formed  consisting  of 

Au  Cl3  +  4  Na  O  =  Au  03  Na  O  +  3  Na  CI. 

The  salt  of  gold  will  readily  be  reduced  by  the  silver.  After  a 
short  time,  however,  the  loosely  combined  oxygen  will  combine  with 
the  NaCl,  particularly  in  the  presence  of  an  excess  of  a  free  alkali, 
and  a  subchlorate  of  soda  and  a  peroxide  of  gold  and  soda  will  be 
formed.* 

Au  03Na  O  +  NaCl  =  Au  O  Na  O  +  Na  O  CI  O. 

The  peroxide  of  gold  and  soda  is  in  the  presence  of  an  excess  of  an 
alkali  so  constant  that  it  cannot  be  reduced  by  silver. 

When  such  a  bath  is  mixed  with  hydrochloric  acid,  it  turns  yellow, 
and  chloride  of  gold  is  formed.    Every  bath  which  has  been  neutral. 


*  The  translator  is  not  quite  confident  that  he  has  given  exactly  the  proper 
chemical  nomenclature ;  the  symbols  will,  however,  explain. 


172 


THE  PRACTICE  OF  PHOTOGRAPHY. 


ized  by  alkalies  has  to  suffer  this  change.  When,  however,  no  alka- 
lies are  present  in  excess,  or  when  they  are  neutral,  they  maintain 
their  toning  power,  as  the  acid  salt  of  gold  which  is  formed  remains 
reducible  in  the  absence  of  an  excess  of  an  alkali.  Only  the  toning 
action  is  somewhat  changed. 

In  a  bath  which  has  not  been  decomposed  only  one  atom  of  gold 
will  be  precipitated  in  the  place  of  three  atoms  of  silver. 

Au03  +  3  Ag=  AgO+Au. 

While  in  a  decomposed  bath,  one  atom  of  gold  will  take  the  place 
of  one  atom  of  silver. 

Au  O  -f  Ag  =  Ag  O  -f  Au. 

In  the  latter  case  the  precipitate  is  more  plentiful ;  the  picture  re- 
tains in  such  a  bath  more  vigor  than  in  one  containing  an  oxide  of 
gold,  in  which  the  intensity  is  always  somewhat  reduced.  A  bath  of 
the  former  composition  is  more  suitable  to  the  toning  of  under-printed 
pictures. 

A  peculiar  kind  of  toning  baths  are  the  so-called  soda  baths ;  they 
are  made  by  adding  drop  by  drop  a  gold  solution  to  a  solution  of 
hyposulphite  of  soda. 

A  double  salt  is  formed  consisting  of  hyposulphite  of  soda  and  an 
aureous  hyposulphite,  which  acts  analogous  to  an  alkaline  bath ;  but 
even  with  an  excess  of  hyposulphite,  it  remains  reducible. 

These  baths  are  used  after  fixing,  while  otherwise  the  toning  pre- 
cedes the  fixing. 

The  tones  are  not  so  pleasant  as  the  ordinary  gold  bath.  The  color 
is  decidedly  brownish,  and  the  pictures  require  a  second  fixing  to  give 
them  permanence. 

The  double  salt  of  Khodan  gold  and  Khodan  ammonia  gives  better 
results. 

What  has  been  said  above  will  suffice  to  make  the  chemical  process 
of  toning  understood.  We  will  now  give  a  number  of  practical  for- 
mulae. 

NORMAL  GOLD  SOLUTION,  AND  THE  CONSUMPTION  OF  GOLD. 

We  use  for  the  gold  bath,  solutions  of  a  certain  strength  of  chlo- 
ride of  gold  and  potassium.  This  salt,  when  purchased  from  the 
trade,  is  generally  pure,  is  not  influenced  by  the  atmosphere,  and  is 
much  easier  kept  than  the  constantly  moist  chloride  of  gold.  As  a 
normal  gold  solution  we  use 

1  part  of  chloride  of  gold  and  potassium, 

50  parts  of  water. 
Of  this  solution  we  take  a  certain  quantity  for  immediate  use. 


PREPARATIONS  —  ALKALINE  TONING  BATHS.  173 

On  a  sheet  of  paper  (17  X  22),  about  0.01  gramme  metallic  gold 
will  be  precipitated,  besides  a  certain  quantity  of  the  fluid  will  be 
taken  up  by  the  paper,  containing  about  0.01  to  0.015  gramme  of 
gold ;  so  that  on  an  average  every  sheet  of  paper  requires  about  0.03 
gramme  of  the  gold  salt.  But,  including  all  the  losses,  we  have  to 
calculate  double  the  quantity  of  gold,  or  0.06  gramme,  equal  to  1 
grain  of  gold  for  every  sheet  of  paper. 

1.  ALKALINE  GOLD  TONING  BATHS. 

a.  Borax  and  Phosphate  of  Soda  Bath. 

For  every  sheet  of  paper 

3  parts  of  normal  solution, 

1£     "     borax,  or  phosphate  of  soda, 

previously  dissolved  in 

JXtk  200       "  water. 

The  borax  solution  can  be  kept  on  hand  in  a  stock-bottle,  and  it 
will  only  be  necessary  to  measure  the  proper  quantity. 

Borax  and  phosphate  of  soda  are  salts  with  an  alkaline  reaction ; 
they  reduce  the  bath  in  exactly  the  same  manner  as  a  free  alkali 
would.  The  weak  boric  and  phosphoric  acids  which  become  free  have 
no  marked  influence. 

The  bath  will  keep  only  for  a  short  time ;  it  should  always  be  made 
fresh.  When  the  temperature  is  low,  it  is  advisable  to  warm  it  before 
use.* 

b.  Chloride  of  Lime  Bath. 

An  addition  of  chloride  of  lime  to  the  toning  bath  is  in  use  by  many 
photographers.  The  effect  is  that  it  makes  the  bath  more  alkaline  (in 
consequence  of  the  presence  of  caustic  lime),  and  furnishes,  therefore, 
blacker  tones.  It  is  formed  in  the  following  manner :  by  adding  to 
the  acetate  of  soda  toning  bath  (see  below)  0.03  gramme  chloride  of 
lime,  shaking  it  well,  and  use  after  leaving  it  stand  about  three  hours. 
The  bath  will  furnish  violet  black  tones.  Grasshoff  prepared  the 
chloride  of  lime  toning  bath  as  follows :  1000  grammes  distilled  water, 
10  grammes  acetate  of  soda  (recrystallized),  J  gramme  chloride  of 
lime,  1  gramme  chloride  of  gold,  or  chloride  of  gold  and  potassium  ; 
the  ingredients  are  shaken  right  well,  and  after  several  hours  (better 
next  day)  several  rejected  prints  (about  6  to  8  card  size)  are  thrown  in 


*  The  author  generally  uses  the  borax  bath. 


174 


THE  PRACTICE  OF  PHOTOGRAPHY. 


without  previous  washing,  and  left  in  about  10  to  15  minutes.  The 
bath  will  turn  very  cloudy,  and  the  prints  very  peculiar  tones.  After 
removal  of  the  prints,  the  washed  prints  are  toned  with  it  in  the  usual 
manner,  toning  pretty  fast  the  first  few  days,  1  gramme  of  gold  toning 
11  to  12  sheets  very  easily,  but  they  must  not  be  toned  too  blue.  If  the 
toning  bath  tones  slower,  add  a  few  drops  of  a  solution  (15  to  16  drops 
per  sheet),  1  part  chloride  of  gold,  or  gold  and  potassium,  in  15  parts  of 
water  occasionally.  Every  four  to  six  days,  a  very  little  chloride  of 
lime  (T'o  to  ^  gramme  is  a  great  deal)  is  added ;  blacker  tones  are  the 
result.  The  clouded  toning  bath  is  filtered  every  three  or  four  days. 
(Photographische  MittheiL,  vol.  vii,  page  150.)  Mr.  Paget  writes  in 
the  News,  that  he  toned  prints  just  from  the  frame,  washed  in  three 
waters  in  an  acetate  of  soda  toning  bath,  in  which  they  toned  very  well. 
However,  a  bath  of  the  following  preparation  would  not  tone  at  all, — 
chloride  of  lime  1^  grammes,  chloride  of  gold  1  gramme,  carbonate  of 
potash  12  grammes,  water  4800  grammes.  They  commenced  toning, 
however,  very  slowly,  as  soon  as  several  unwashed  prints  were  thrown 
in.  According  to  this,  nitrate  of  silver  is  necessary  to  a  chloride  of 
lime  toning  bath.  Bovey  therefore  recommends  the  washing  of  the 
prints  in  only  two  changes  of  water  before  toning.  For  this  reason 
GrasshofF  throws  several  unwashed  prints  into  the  lime  toning  bath. 
According  to  Abney,  a  thoroughly  washed  print  will  not  tone  in  a 
chloride  of  lime  toning  bath  free  from  nitrate  of  silver  inside  of  fifteen 
minutes,  but  on  the  contrary  is  bleached,  and  produces  fox-colored' 
pictures. 

If,  however,  the  washed  print  is  dipped  into  a  solution  of  nitrate  of 
lead,  it  will  tone  rapidly  of  a  peculiar  color  different  than  if  silver 
were  present.  A  toning  bath  of  3  grains  chloride  of  gold  and  20 
ounces  of  water  would  not  tone  washed  prints  inside  of  fifteen  minutes, 
but  only  bleach  them.  Partly  washed  prints,  however,  tone  in  five 
minutes;  also  pictures  soaked  in  nitrate  of  lead.  It  proved  that  this 
bath  contained  hypochloric  acid  (produced  by  the  action  of  the  chlo- 
rine in  the  gold  on  the  lime).  If  chloride  of  lime  was  added  to  the 
bath  it  toned  more  regular.  Abney  concludes  from  his  experiments, 
1.  That  a  metallic  salt  which  absorbs  chlorine  is  necessary  in  a  chloride 
of  lime  toning  bath.  2.  That  chloride  of  lime  acts  as  a  retarder  in  ton- 
ing. 3.  In  a  pure  acetate  of  soda  (without  chloride  of  lime)  toning 
bath,  the  presence  of  free  nitrate  of  silver  is  prejudicial. 


PREPARATIONS 


—  ACID  TONING  BATHS. 


175 


NEUTRAL  GOLD  BATHS. 

a.  With  Chalk  (after  Davanne). 
A  sheet  of  paper  will  require 

3  cubic  centimetres  of  normal  solution,* 
200  water, 

Chalk,  or  carbonate  of  lime,  as  much  as  can  be  placed  on  the  point  of 
a  knife. 

The  mixture  has  to  be  shaken  for  about  live  minutes  and  then 
filtered.  The  solution  will  look  yellow  when  freshly  made,  but  will 
become  colorless  after  a  few  hours,  without,  however,  losing  its  toning 
properties  ;  but  it  will  tone  slower.  Pure  carbonate  of  lime  is  prefer- 
able to  chalk,  as  the  latter  contains  organic  substances  which  decom- 
pose the  gold  salt. 

b.  With  Bicarbonate  of  Soda. 

Gold  solution  and  water  should  be  taken  as  above,  and  a  solution 
of  bicarbonate  of  soda  should  be  added  drop  by  drop,  stirring  the 
liquid  constantly,  until  blue  litmus-paper  is  no  longer  reddened. 
This  bath  does  not  keep ;  with  an  excess  of  soda  it  becomes  alkaline, 
and  the  tones  become  black.  As  mistakes  are  apt  to  occur  in  making 
it,  we  give  the  following  formula  of  Mr.  England  : 

3  cubic  centimetres  of  normal  gold  solution, 

3        "  "       "  a  solution  of  crystallized  bicarbonate  of  soda,  1  :  50, 

200        "  "       "  water. 

The  mixture  should  be  used  half  an  hour  after  it  has  been  prepared. 
The  bath  does  not  keep,  and  should  always  be  prepared  fresh. 

3.  ACID  TONING  BATHS. 

The  Acetate  of  Soda  Bath. 

For  every  sheet  of  paper 

3  cubic  centimetres  of  normal  solution, 
2  grammesf  of  crystallized  acetate  of  soda, 
previously  dissolved  in 
200  grammes  of  water, 

should  be  taken. 


*  A  cubic  centimetre  is  equal  to  17  minims, 
f  A  gramme  is  equal  to  15.434  grains. 


176 


THE  PRACTICE  OF  PHOTOGRAPHY. 


The  bath  should  be  used  twenty-four  hours  after  it  has  been  made, 
and  it  is  only  necessary  to  strengthen  it  from  time  to  time  with  a  few 
drops  of  normal  solution.    It  gives  brownish  tones. 

4.  RHODAN  GOLD  BATH. 

I  do  not  recommend  hyposulphite  of  soda  baths.  Amongst  the 
many  that  have  been  suggested,  I  have  not  found  a  single  one  which 
has  given  me  satisfaction.  But  the  Khodan  gold  bath  deserves  to  be 
recommended. 

It  yields  the  richest  gradations  in  tone  that  a  bath  is  capable  of, 
according  to  the  length  of  toning.  The  fixing  with  "  hypo  "  changes 
the  tone  a  little. 

The  pictures  do  not  require  as  much  overprinting  as  with  other 
baths,  a  considerable  advantage  in  dark  and  cloudy  weather.  The 
picture  is  washed  after  printing,  and  placed  in  the  following  toning 
bath : 

Gold  solution,  3  cubic  centimetres. 

Sulphocyanide  of  ammonium,      .       .      20  grains. 
Previously  dissolved  in,  100  grains  of  water. 

The  picture  turns  at  first  pale  and  reddish,  but  finally  becomes 
warm  and  brilliant,  and  passes  from  brown  to  violet,  and  finally  to 
black.  This  bath  consumes  a  little  more  gold,  perhaps  as  much  as  2 
grains  per  sheet  of  paper. 

The  bath  is  kept,  and  can,  by  adding  from  time  to  time  a  few  drops 
of  gold  solution,  be  used  over  and  over  again. 

The  proportion  should  be  kept  in  the  above  toning  bath  (3  cubic 
centimetres  of  normal  gold  solution  contain  0.06  of  the  gold  salt). 
As  for  the  formula  to  be  selected,  we  must  refer  to  what  has  been 
said  above  in  regard  to  the  neutral,  alkaline,  and  acid  bath,  which 
will  give  the  reader  sufficient  information.  It  would  be  superfluous, 
and  perplexing  for  the  beginner,  to  give  him  more  formulae  to  select 
from.  Any  one  who  likes  black  tones  should  select  the  carbonate  of 
soda  or  chloride  of  lime  bath.  To  any  one  desiring  brown,  I  recom- 
mend the  acetate  gold  bath,  and  for  purple  violet  the  borax  or  chalk 
bath.    I  generally  employ  the  former. 

THE  FIXING  BATH. 

Hyposulphite  of  soda  is  used  for  fixing  prints ;  cyanide  of  potassium 
is  not  admissible,  as  it  affects  the  pictures  very  much.    The  Khodan 


THE  SILVER  PRINTING  PROCESS. 


177 


ammonium  has  never  been  used  much,  partly  on  account  of  its  high 
price,  partly  also  because  it  necessitates  the  use  of  two  fixing  baths. 
Take  a  fresh  solution  of, 

2  parts  of  hyposulphite  of  soda. 
4-5       "  water. 

Solutions  that  have  been  used  previously  will  decompose  rapidly, 
and  the  pictures  are  apt  to  turn  yellow. 

FAULTS  OF  THE  PAPER. 

In  the  photographic  practice  of  the  silver  printing  process  the  albu- 
men paper  is  most  generally  employed.  It  is  very  seldom  made  in 
the  atelier,  bu"t  is  generally  bought  from  the  dealer. 

Its  quality  is,  even  with  the  same  mode  of  manufacture,  very  vari- 
able. The  white  of  egg  shows  in  winter  different  qualities  from  what 
it  does  in  summer. 

The  tendency  to  change  in  this  least  stable  substance  is  so  great 
that  it  is  almost  impossible  to  furnish  always  the  same  quality,  and 
the  complaints  about  the  albumen  paper  will  continue  as  long  as  the 
silver  printing  process. lives. 

Some  papers  discolor  the  silver  bath  in  consequence  of  the  dissolu- 
tion of  a  part  of  the  organic  substances  ;  others  turn  yellow  a  short 
time  after  sensitizing,  tone  badly,  and  become  spotted  in  the  fixing 
bath. 

The  number  of  these  faults  is  legion,  and  their  origin  is  by  no 
means  perfectly  understood.*  Experience  has  taught  us  that  albu- 
men paper  works  better  when  it  is  not  too  dry,  and  that  imperfect 
papers  yield  better  results  with  a  concentrated  bath  than  with  a  di- 
luted one.  It  is  recommendable  to  place  the  paper  for  twenty-four 
hours  in  a  damp  place,  previous  to  sensitizing.  The  blisters  which 
are  apt  to  make  their  appearance  on  fixing,  particularly  in  summer- 
time, are  by  it  avoided.  It  is  a  mistake  to  try  to  preserve  albumen 
paper  with  chloride  of  calcium  in  closed  boxes. 

SECTION  II. 

THE  PRACTICE  OF  THE  SILVER  PRINTING  PROCESS. 

In  the  practice  of  the  printing  process  a  perfect  negative  is  supposed 
to  be  at  hand.    The  back  of  it  should  be  carefully  cleaned.    If  the 

*  The  manufacturer  is  not  always  to  be  blamed,  for  very  often  the  fault  lies 
with  the  photographer. 

12 


178 


THE  PRACTICE  OF  PHOTOGRAPHY. 


latter  is  much  covered  by  the  retouch,  it  is  well  to  varnish  the  same 
similarly  to  the  front.  The  cleaned  negative  is  placed  into  the  print- 
ing-frame. The  pieces  of  plate-glass  are  carefully  cleansed,  the  nega- 
tive is  placed  on  top  of  it,  and  the  sensitized  paper,  perfectly  dry,  is 
placed  on  the  negative. 

SENSITIZING  THE  PAPER. 

The  printing  bath  should  be  filtered  into  a  clean  glass  or  porcelain 
dish.  A  strip  of  writing-paper  should  be  drawn  several  times  over 
the  bath  to  remove  the  scum  ;  the  paper  should  now  be  placed  on  the 
bath.  This  work  does  not  require  an  absolutely  dark  room,  as  the 
paper  is  not  sensitive  enough  to  be  influenced  much  b^  diffused  day- 
light. 

The  paper  should  next  be  cut  into  pieces  of  suitable  size  (when  a 
large  quantity  of  prints  is  to  be  made  it  is  advisable  to  sensitize  whole 
sheets) ;  the  albumen  surface  should  be  touched  as  little  as  possible 
in  cutting ;  the  paper  should  be  folded  with  the  albumen  side  up- 
wards, and  the  fold  should  be  cut  from  the  outside  with  the  scissors. 
This  avoids  the  soiling  of  the  paper  with  rust,  which  is  afterwards  apt 
to  give  rise  to  black  spots.  The  greatest  cleanliness  of  the  tables,  on 
which  the  silvered  and  unsilvered  paper  is  placed,  cannot  be  too  often 
recommended. 

The  paper  is  placed  on  the  bath  by  seizing  it  on  two  opposite  cor- 
ners ;  the  central  part  is  lowered  until  it  touches  the  bath,  and  the 
whole  sheet  is  gradually  let  down  on  the  liquid.  The  movement  must 
not  be  interrupted,  as  streaks  and  lines  would  be  the  consequence. 

Air-bubbles  under  the  paper  will  frequently  prevent  the  proper 
sensitizing  of  the  paper ;  to  remove  them  the  paper  should  be  lifted 
by  one  corner ;  the  bubbles  should  be  removed  by  a  glass  rod,  and 
the  paper  placed  on  the  bath  again. 

The  duration  of  the  floating  depends  on  the  strength  of  the  bath, 
the  temperature,  the  albumen,  and  it  is  very  variable.  In  summer 
three  minutes,  in  winter  four  minutes,  are  generally  sufficient.  A 
sand-glass  is  very  convenient  for  timing.  Great  care  should  be  taken 
to  prevent  the  solution  from  touching  the  back  of  the  paper,  as  this  inva- 
riably gives  rise  to  spots.  When  the  paper  is  sensitized  it  should  be 
carefully  removed  from  the  bath  by  lifting  it  by  one  corner,  and 
placed  in  a  dark  room  to  dry.  At  77°  Fahr.  the  paper  dries  very 
rapidly.  When  the  temperature  is  low  a  lamp  will  often  very  mate- 
rially assist  in  drying,  but  great  care  should  be  taken  not  to  scorch  the 
paper.  The  dried  paper  should  be  examined  carefully,  as  sometimes 
at  the  corners,  sometimes  in  the  centre,  damp  spots  will  be  found ; 


SENSITIZING  THE  PAPER. 


179 


these  stick  to  the  negative,  and  many  an  excellent  plate  has  been 
ruined  by  it. 

The  dry  papers  should  be  treated,  in  regard  to  handling  them,  even 
more  carefully  than  the  unsensitized  albumen  paper.  It  should  be 
placed  into  a  clean  box,  and  carried  in  this  to  the  printing-room.  A 
condition  for  a  sharp  picture  is  the  intimate  contact  between  negative 


and  paper;  this  can  only  be  reached  by  strong  pressure.  With 
curved  plates  we  run  the  risk  of  breaking  them ;  even  with  level 
plates  we  run  this  risk,  when,  as  is  often  the  case,  glass  splinters  or 
grains  of  sand  are  present  in  the  copying-frame.  The  paper  should 
be  placed  with  the  sensitive  side  flat  against  the  negative ;  a  piece  of 
oilcloth  should  be  placed  on  this ;  and  then  a  pad,  consisting  of  soft 
paper  or  felt,  should  form  the  final  layer ;  the  cover  is  now  laid  on, 
the  springs  are  fastened,  and  the  printing  may  commence. 

Some  papers  curl  up  in  drying,  and  do  not  lay  smoothly  in  the 
printing-frame,  particularly  when  they  are  too  dry,  or  when  the 
printing  is  done  in  a  cold  room ;  when  this  is  the  case  it  is  well  to 
place  the  paper,  after  silvering,  in  a  cool  place,  or  place  behind  it  a 
piece  of  cardboard ;  next  open  one  side  of  the  frame,  and  draw  the 
paper  straight ;  then  open  the  other  half  of  the  frame,  and  draw  the 
other  side  straight.  The  frame  should  not  be  exposed  to  the  light 
until  we  feel  fully  convinced  that  the  contact  is  perfect. 

The  fuming  with  ammonia  is  in  almost  universal  use  in  the  United 
States.  It  has  the  advantage,  that  a  diluted  bath  (1  salt  of  silver 
and  20  water)  which  alone  would  yield  poor  prints,  will  work  well, 
and  yield  good  pictures.  Fumed  paper  will  also  print  more  rapidly, 
and  has  deeper  blacks,  as  well  as  clearer  whites.  With  a  strong  silver 
bath  fuming  is  of  little  benefit.  In  the  dry  atmosphere  of  many  parts 
of  the  United  States  the  fuming  with  ammonia  has  the  other  advan- 
tage, that  a  certain  amount  of  moisture  is  imparted  to  the  paper. 
The  dry  silvered  paper  is  placed,  for  from  ten  minutes  to  half  an 


Fig.  70. 


180 


THE   PRACTICE  OF  PHOTOGRAPHY. 


hour,  in  a  closet,  on  the  bottom  of  which  a  dish  with  ammonia  has 
been  placed. 

In  Europe  we  employ  the  fuming  process  very  seldom. 

THE  PRINTING. 

When  all  the  frames  have  been  supplied  with  paper  they  are 
placed  in  the  light.  They  should  be  so  arranged  that  plates  of  equal 
density  are  placed  together.  It  will  then  only  be  necessary  to  ex- 
amine one  frame  from  time  to  time,  and  from  the  result  we  can  judge 
of  the  rest. 

The  exposure  is  much  longer  than  when  making  the  negative. 
With  dense  positives,  and  dark  or  cloudy  weather,  it  may  take  days, 
and  sometimes  the  paper  will  turn  yellow  before  the  print  is  finished. 
A  tolerably  good  judgment  can  be  formed,  by  watching  the  edges  of 
the  paper  which  protrude  from  under  the  negative ;  these  become 
bronzed,  and  the  negative  picture  commences  to  show  as  a  positive. 
But  to  be  perfectly  informed  in  regard  to  the  progress  of  the  work 
the  prints  should  be  examined  from  time  to  time  ;  the  frame  is  taken 
into  the  room,  and  in  a  place  that  is  not  too  light,  one-half  of  the 
back  is  opened,  the  print  is  examined,  the  lid  is  closed  again,  and 
now  the  other  half  is  examined  in  the  same  manner.  Care  should  be 
taken  not  to  move  the  paper,  in  order  that  on  closing  the  lid  it  will  re- 
sume its  original  position. 

The  print  is  finished  when  the  finest  details  in  the  high  lights  have 
become  visible,  when  the  protruding  corners  have  become  bronzed,  and 
when  the  intensity  of  the  whole  print  is  a  little  in  excess  of  ivhat  is  desired 
in  the  finished  picture. 

The  latter  is  necessary,  because  some  intensity  is  always  lost  in 
toning.  Experience  only  can  determine  the  proper  degree  to  which 
printing  may  be  carried;  it  depends  also  on  the  character  of  the  nega- 
tive, and  the  kind  of  gold  bath  that  is  to  be  used. 

PRINTING  VIGNETTES. 

To  produce  pictures  in  which  the  background  gradually  changes 
from  dark  to  white,  it  is  necessary  to  cover  the  negative  with  a  vign- 
ette frame.  This  consists  sometimes  of  a  glass  plate  which  is  bright 
in  the  centre,  and  becomes  gradually  darker  towards  the  margin,  or 
simply  of  a  piece  of  pasteboard,  in  which  a  hole  has  been  cut  corre- 
sponding with  the  figure  on  the  negative.  This  piece  of  pasteboard  is 
placed  on  the  printing-frame.  By  removing  it  further  from  the  nega- 
tive the  gradation  of  tone  will  become  more  gentle  and  gradual. 
Waymouth's  Vignette  Papers  are  the  most  modern  invention  and  are 
capital. 


COMBINATION  PRINTING. 


181 


Care  should  be  taken  that  the  papers  do  not  change  their  posi- 
tion ;  side-light  also  should  be  excluded,  as  it  may  give  rise  to  unde- 
sirable discolorations.  It  is  best  to  nail  the  pasteboard  on  to  the 
printing-frame.  When  large  quantities  of  prints  are  to  be  made, 
vignette-frames  of  sheet-iron  are  advantageous.  When  white  paste- 
board is  used,  it  should  be  blackened.  Vignetting  is  of  great  advan- 
tage when  the  background  is  faulty. 

PRINTING  OF  IMPERFECT  NEGATIVES. 

The  printing  rules  which  we  have  given  will  suffice  for  a  perfect 
negative,  which  has  brilliant  but  not  too  dense  lights,  and  shows 
details  in  the  shadows.  But  we  frequently  have  weak  negatives,  in 
which  all  the  details  in  the  lights  have  made  their  appearance  before 
the  shadows  have  gained  sufficient  strength. 

These  are  best  printed  under  a  piece  of  green  glass.  Experience 
has  taught  us  that  with  a  feeble  light  the  contrasts  become  stronger, 
or,  what  is  the  same,  the  shadows  become  darker  and  the  lights 
brighter. 

Another  way  is  to  cover  the  back  of  the  negative  with  varnish  in 
which  a  little  dragon's  blood  has  been  dissolved.  This  varnish  will 
weaken  the  light  similarly  to  the  green  glass.  On  the  other  hand,  we 
may  have  strong  hard  negatives,  in  which  the  shadows  would  be 
completely  burned  up,  if  we  would  print  until  the  details  appear  in 
the  lights.  We  can  then  help  ourselves  by  covering  the  black  sur- 
faces, when  they  have  reached  sufficient  density,  by  suitably  cut  pieces 
of  pasteboard  (masks).  Small  portions  of  the  lights,  that  are  too  dense 
to  print  properly,  can  be  brought  out  by  condensing  light  on  them 
with  a  lens. 

PRINTING  WITH  SEVERAL  NEGATIVES  (COMBINATION  PRINTING). 

It  is  requisite  sometimes  to  make  use  of  several  negatives,  or  parts 
of  each  for  one  print,  similarly  to  lithography,  where  several  plates  are 
used  on  one  sheet.  Work  of  this  kind  requires  great  accuracy,  and 
is  not  very  easy,  especially  in  pigment  printing  (see  below).  Take  a 
printing-frame  which  has  good  strong  hinges  attached  to  the  lid. 
On  this  the  negative  is  fastened  with  screws.  The  paper  is  fastened 
on  the  lower  part.  If,  for  instance,  a  portrait  with  landscape  back- 
ground is  desired,  the  portrait  is  printed  first  in  the  above  frame, 
everything  else  being  covered  on  the  plate.  Then  the  landscape 
negative  is  placed  in  the  frame,  in  which,  contrary  to  the  other, 
nothing  but  the  space  for  the  figure  is  covered.    For  this  purpose  a 


182 


THE  PRACTICE  OF  PHOTOGRAPHY. 


print  of  the  figure  is  made  and  cut  out  carefully,  darkened  in  the 
light,  and  laid  with  great  accuracy  on  the  print  in  the  printing- 
frame,  so  that  the  figure  will  be  covered.  To  prevent  the  mask  from 
moving,  a  little  gum  is  placed  on  it ;  it  has  also  been  proposed  to  edge 
the  printing-frame  with  caoutchouc  solution.  In  closing  the  frame 
the  mask  will  adhere  to  the  landscape  negative.  In  this  manner  two 
negatives  fitting  together  can  be  made,  by  means  of  which,  without 
much  trouble,  a  number  of  prints  can  be  produced,  using  one  for  the 
figure  and  the  other  for  the  background.  It  must  always  fit  together 
without  necessitating  an  inspection,  which  in  pigment  printing  is  very 
important.  The  main  point  is  to  lay  the  plates  always  on  the  righ't 
place,  which,  in  the  construction  of  the  frame,  is  easily  accomplished  ; 
the  negatives,  however,  must  be  of  one  size.  If  this  is  not  the  case  they 
must  be  previously  fastened  to  a  large  glass-plate.  This  frame  will 
answer  very  well  for  printing  on  glass-plates.    (See  next  chapter.) 

MEZZOTINTS  (HALF-TONE  PICTURES). 

There  is  often  complaint  made  that  photographic  prints  are  im- 
moderately sharp,  and  create  thereby  a  bad  effect.  This  in  fact  is 
the  case  with  certain  sharp  features,  wrinkles,  and  freckles  in  the 
face.  This  immoderate  sharpness  is  considerably  mitigated  and 
the  picture  receives  a  more  porcelain  effect  by  placing  between  the 
negative  and  print  a  thin  transparent  substance.  Take  sheet  gela- 
tin, which  can  be  purchased  at  the  dealers,  or  prepared  as  follows : 
A  large  piece  of  plate-glass  is  surrounded  by  a  wooden  frame,  washed 
clean,  dried,  and  rubbed  on  one  side  with  oxgall ;  when  this  is  dry, 
a  solution  of  gelatin  middling  warm  is  poured  on,  spread  evenly, 
and  set  away,  protected  from  dust,  to  dry,  which  will  take  one  to  two 
days.  The  edges  are  then  slightly  cut  with  a  knife ;  the  gelatin  will 
spring  off.  Instead  of  oxgall,  plain  collodion  can  be  used.  The  prints 
are  printed  in  the  usual  manner  until  three-quarters  done,  then  place 
one  or  two  pieces  of  gelatin  between  the  negative  and  print,  according 
to  the  effect  desired,  which  is  merely  a  matter  of  taste,  and  finish  as 
usual.  This  style  of  printing  furnishes  nice  delicate  half-tones,  which, 
however,  have  a  waxen  appearance.  The  same  result  can  be  obtained 
by  placing  two  thin  negatives  (exactly  alike)  on  top  of  each  other, 
and  printing  from  them. 

OVAL  PICTURES  (MEDALLIONS)  ON  A  GRAY  OR  BLACK  GROUND. 

Pictures  of  this  kind  are  produced  as  follows :  An  oval  is  cut 
out  of  a  piece  of  black  paper,  the  outside  is  placed  on  the  negative 


THE  TONING. 


183 


and  printed ;  the  outside,  or  part  covered  by  the  paper,  will  remain 
white.  The  figure  is  then  covered  with  the  oval  previously  cut  out, 
and  printed  to  any  depth  desired.    See  Hearn's  "Practical  Printer.11 

THE  WATERING. 

The  prints  are  taken  from  the  frames  and  placed  in  a  dark-box, 
but  not  in  the  same  one  in  which  the  sensitized  papers  are  kept. 
When  all  the  prints  are  finished,  they  should  be  treated  in  the  fol- 
lowing manner : 

To  keep  prints  till  the  following  day  is  only  advisable  when  we  are 
sure  that  the  paper  will  not  turn  yellow. 

The  paper  absorbs  from  the  bath  a  considerable  quantity  of  nitrate 
of  silver ;  of  this  only  the  smallest  portion  is  reduced  by  the  light, 
and  in  the  printed  picture  a  considerable  quantity  of  free  nitrate  of 
silver  remains.  By  decomposing  the  gold  this  substance  would  act 
very  injuriously  on  the  toning  bath  if  it  were  permitted  to  remain.* 
The  nitrate  is  removed  by  washing.  Gutta-percha  dishes  will  answer 
for  this  purpose  ;  they  are  less  liable  to  breakage  than  porcelain  or 
glass  dishes.  It  should,  however,  he  a  rule  to  use  these  dishes  for  no 
other  purpose,  and  the  washing  should  he  done  on  a  table  where  an  ad- 
mixture with  other  chemicals,  particularly  hyposulphite  of  soda,  is  not  to 
he  feared.  The  sheets  are  placed,  one  after  the  other,  with  perfectly 
clean  fingers,  into  a  dish  which  is  filled  with  clean  water ;  each  sheet 
should  be  perfectly  wetted  ;  generally  the  water  turns  milky  in  con- 
sequence of  the  separation  of  chloride  of  silver.  After  ten  minutes 
the  prints  are  removed  from  the  first  dish  into  a  second  one,  and  the 
milky  liquid  is  poured  in  the  barrel  for  silver  residues.  The  same  is 
done  with  the  water  of  the  second  dish.  When  they  have  been 
washed  in  five  or  six  changes  of  water,  or  when  the  water  no  longer 
appears  milky,  the  washing  may  be  considered  complete.  It  is  not 
worth  the  trouble  to  save  the  water  from  the  last  two  washings.  The 
washing  should  be  done  in  a  dimly  lit  room,  otherwise  the  whites  may 
suffer. 

THE  TONING. 

The  picture  should  be  toned  as  soon  as  the  washing  is  finished.f 
The  toning  bath  should  be  placed  in  a  dish  which  is  solely  devoted  to 
this  purpose ;  the  bath  should  be  warmed  a  little  in  winter-time.  One 


*  When  nitrate  of  silver  is  mixed  with  chloride  of  gold,  chloride  of  silver 
and  metallic  gold  will  be  formed,  and  oxygen  and  nitric  acid  will  become  free. 

f  Pictures  which  remain  for  a  long  time  in  water  (say  about  twelve  hours) 
often  suffer  decomposition  and  tone  unevenly. 


184  THE  PRACTICE  OF  PHOTOGRAPHY. 

print  after  another  should  be  immersed  in  the  bath,  with  clean  fingers 
and  while  agitating  the  bath  constantly.  It  is  necessary  that  the 
gold  solution  wets  the  pictures  equally,  otherwise  unequal  toning  will 
be  the  consequence.  The  change  of  color  in  the  pictures  is  readily 
noticed ;  soon  after  immersion  they  assume  a  brownish  violet  tint, 
they  next  turn  violet,  violet  blue* and  finally  blue  or  slate  color.  As 
soon  as  the  desired  tone  has  been  reached  (violet  or  violet  blue  is 
probably  the  most  generally  liked),  the  pictures  are  taken  from  the 
bath  and  thrown  into  a  dish  of  water.  The  toning  should  also  be 
done  in  a  semi-dark  room,  otherwise  the  whites  may  suffer.  Daylight 
is  better  than  lamplight  (but  when  we  are  compelled  to  use  lamplight, 
the  lamp  should  be  placed  as  close  as  possible  to  the  dish).  The  most 
practical  way  is  to  place  three  dishes  alongside  of  each  other.  To  the 
left  a  dish  with  the  pictures  in  water,  in  the  centre  the  gold  bath,  and 
to  the  right  another  dish  with  water.  No  more  pictures  should  be 
thrown  into  the  bath  at  once  than  what  we  are  able  to  control,  other- 
wise we  run  the  risk  of  overtoning.  Pictures  on  plain  paper  tone 
more  rapidly  than  those  on  albumen  paper.  For  the  former  a  very 
dilute  gold  bath,  or  one  which  has  been  partially  exhausted  by  being 
previously  employed  for  albumen  prints,  should  be  used. 

THE  FIXING. 

The  fixing  should  be  done  in  a  dish  especially  devoted  to  that  pur- 
pose. One  by  one  the  prints  are  taken  from  the  water  and  placed 
into  the  fixing  solution.  The  dish  should  be  moved  in  order  that  the 
liquid  may  flow  at  once  over  the  print.  Great  care  must  be  taken 
to  keep  the  fingers  free  from  soda  solution,  as  a  toned  print,  which  has 
been  handled  with  "  soda  fingers  "  previous  to  fixing,  will  invariably 
show  spots.  Many  use  wooden  forceps  for  "  handling  "  the  unfixed 
prints. 

The  pictures  assume  an  unpleasant  tone  in  the  soda  bath,  very 
brown  when  the  time  allowed  for  toning  has  been  very  short,  at  the 
same  time  they  become  paler.  Beginners  must  not  be  deceived  by 
this.  The  tone  improves  after  washing  and  drying,  and  finally  the 
intensity  becomes  the  same  which  the  pictures  showed  in  the  toning  hath. 

The  latter  can  be  used  as  a  guide.  The  duration  of  the  fixing  pro- 
cess is  at  least  five  minutes.  Until  the  fixing  process  is  finished  the 
whites  in  the  pictures  will  appear  mottled  or  cloudy. 

THE  WASHING  AFTER  FIXING. 

In  the  fixed  picture  a  considerable  quantity  of  hyposulphite  of 


THE  WASHING  AFTER  FIXING. 


185 


soda  remains.  If  this  substance  were  permitted  to  stay  in  the  paper, 
decomposition  would  soon  take  place ;  the  sulphur  would  combine 
with  the  silver,  forming  sulphate  of  silver,  and  the  print  would  turn 
yellow.  The  thorough  washing,  the  perfect  removal  of  hyposulphite 
of  soda,  is  hence  very  necessary.  The  simplest  way  to  accomplish  it 
is  by  using  frequent  changes  of  water.  For  an  atelier  the  following 
can  be  recommended.  A  (Fig.  71)  is  a  cistern  of  Japanned  tin,  with 
a  double  bottom  ;  the  upper  one,  B,  is  perforated  with  holes,  like  a 
sieve  ;  H  is  a  siphon  with  its  opening  at  the  lowest  place  of  the  box ; 


It  is  a  pipe,  either  provided  with  small  openings,  or  tubes,  a,  a,  a,  a ; 
this  pipe  is  connected  with  the  water-supply  pipes,  or  with  a  reser- 
voir; the  size  of  the  siphon,  H,  should  be  sufficiently  large,  or  of 
such  a  diameter,  that  the  box  is  twice  as  rapidly  emptied  of  its  con- 
tents, as  the  pipe  R  is  capable  of  filling  it.  The  fixed  pictures  are 
first  placed  in  a  dish  with  clean  water.  The  vessel,  A,  is  now  filled 
with  water,  and  the  pictures  are  placed  in  it  one  by  one  while  the 
water  is  soon  flowing;  as  the  vessel  is  filled  to  the  top  line  of  the 
siphon,  the  latter  commences  to  act,  and  in  spite  of  the  constant  ad- 
dition through  the  pipe,  R,  empties  the  box  in  a  few  minutes ;  as  soon 
as  this  is  done  its  action  ceases.  The  vessel  is  filled  again  with  water, 
and  the  process  repeats  itself.  By  such  an  arrangement  it  is  possible 
to  wash  pictures  perfectly  in  from  one  to  two  hours,  according  to 
quantity ;  care  should  be  taken  that  the  prints  do  not  stick  together ; 
when  this  takes  place  soda  is  apt  to  remain  in  the  paper  in  spite  of 
repeated  washings.  To  avoid  this  sticking  together,  a  rotary  motion 
is  given  to  the  water  by  placing  the  supply-tubes,  a,  a,  a,  in  an  ob- 
lique direction,  as  shown  in  the  figure.  The  pictures  will  float  in  the 
direction  of  the  current,  and  when  the  size  of  the  prints  is  not  large, 
this  arrangement  will  answer.    But  when  we  have  large  prints,  per- 


186 


THE  PRACTICE  OF  PHOTOGRAPHY. 


sonal  inspection  from  time  to  time  and  removal  by  hand  are  necessary ; 
the  washing  should  also  be  continued  as  long  as  possible. 

In  large  establishments  the  prints  are  generally  washed  for  a  whole 
night. 

Mr.  Schade,  in  Sorau,  recommends  a  constant  tilting  of  the  wash- 
box  by  an  electro-magnetic  arrangement. 

Sometimes  the  prints  will  stick  to  the  sides  of  the  box  ;  to  prevent 
this  small  holes  are  made  into  the  lower  side  of  the  pipe,  R,  and  the 
water  which  runs  down  on  the  sides  of  the  box  will  remove  the  prints 
which  stick  to  them. 

To  ascertain  if  the  washing  has  been  carried  far  enough,  the  iodine 
starch  test  of  the  author  is  employed.  When  the  washing  is  finished, 
the  pictures  are  separated  under  water,  and  a  portion  of  the  last  water 
is  taken  from  the  box.  For  the  purpose  of  testing,  two  test-tubes  of 
equal  size,  and  perfectly  clean,  should  be  selected  ;  in  each  an  equal 
quantity  of  a  solution  of  iodide  of  starch*  should  be  placed ;  to  the 
one  tube  fresh  water  from  the  reservoir  is  added ;  to  the  other  an 
equal  quantity  from  the  last  water  in  the  wash-box.  It  is  only  neces- 
sary to  shake  both  tubes  well,  and  to  hold  them  against  a  piece  of 
white  paper,  in  order  to  ascertain  if  in  one  of  the  tubes  a  discoloration 
has  taken  place.  The  greatest  cleanliness  of  the  hands  and  test-tubes 
is  necessary.  Even  with  a  millionfold  dilution,  the  presence  of  soda 
can  be  detected.  When  the  test  shows  that  soda,  or  even  a  trace  of 
it,  is  still  present,  the  washing  should  be  repeated.  When  we  wish  to 
test  finished  pictures  by  this  method,  we  must  soak  them  first  in  water, 
and  then  test  the  water  as  described  above.  The  washed  pictures  are 
dried,  hung  back  to  back  on  clean  cords  in  a  place  free  from  dust. 

Some  operators  place  the  prints  between  blotting-papers ;  here  it 
sometimes  happens  that  with  imperfect  washing  the  blotting-paper 
becomes  gradually  saturated  with  the  soda  and  causes  yellow  spots  on 
the  pictures.  Frequently  fresh  blotting-paper  contains  soda,  as  this 
substance  is  often  added  to  the  paper  pulp  after  bleaching.  To  test 
paper  for  soda,  the  above  described  solution  of  iodide  of  starch  should 
be  dropped  upon  it.    A  discoloration  will  indicate  at  once  the  pres- 


*  Iodide  of  starch  is  made  as  follows :  1  grain  arrowroot  is  mixed  with  a 
few  drops  of  cold  water ;  next  about  100  parts  of  distilled  boiling  water  are 
poured  on  it,  and  afterwards  20  parts  of  chemically  pure  saltpetre  are  added 
to  make  the  paste  keep.  To  the  solution  of  starch  20  grains  of  a  wine-yellow 
solution  of  iodine  in  iodide  of  potassium  solution  is  added  (a  bit  of  iodine 
thrown  into  a  solution  of  iodide  of  potassium,  1  :  20,  will  furnish  this  in  a  few 
seconds).  This  will  give  a  blue  solution  of  iodide  of  starch,  which  will  keep 
for  about  four  weeks. 


THE  FINISHING. 


187 


ence  of  soda.  At  any  rate  the  drying-paper  should  be  changed  very 
frequently. 

THE  FINISHING.  ' 

The  dried  pictures  are  cut  to  the  proper  shape  ;  it  is  best  to  use  a 
sharp  steel  knife,  a  glass  table,  and  glass  ruler  or  form.  Eight- 
angled  and  round  or  oval  guides  are  used,  and  for  the  latter  the 
Kobinson  Trimmer  far  excels  a  knife;  very  seldom  oblique  angles. 
This  will  easily  be  understood  by  drawing  a  straight  line,  a  b,  when 
we  erect  on  it  with  the  guide  a  vertical  line,  c  d,  and  when  we 
place  the  guide*  to  the  right  and  left  of  c  d,  it  has  to  fit  exactly. 
With  smaller  sizes,  as,  for  instance,  cartes  de  visite,  a  glass  plate  of 
the  exact  proportions  is  often  used  to  cut  by.  The  cut  pictures  are 
pasted  on  Bristol-board,  to  give  them  more  firmness.  The  "mount" 
very  often  contains  hypo  ;  in  doubtful  cases  a  test  for  hypo  should 
be  made  with  iodide  of  starch  in  the  manner  described  above. 

The  board  may  be  either  sized  or  not ;  the  latter  are  sometimes 
preferred  on  account  of  cheapness,  when  great  quantities  of  prints 
have  to  be  furnished.  The  pictures  are  pasted  very  easily,  but  have 
the  disadvantage  that  they  will  draw  a  great  deal  in  drying ;  this 
can  be  avoided  by  carefully  dampening  the  back  of  the  mount  pre- 
vious to  pasting  the  print  on  it. 

Very  often  the  mounts  are  tinted :  pale  colors  should  be  selected. 
Care  should  also  be  taken  that  the  signatures,  and  other  printed  matter, 
do  not  contrast  too  glaringly.  When  the  tint  is  laid  on  too  heavy 
it  is  an  impediment  to  pasting.  As  a  mounting  medium  common 
paste  is  most  generally  used.  It  should  always  be  used  fresh,  and 
the  addition  of  salts,  as  for  instance  alum,  should  be  avoided ;  such 
addition  frequently  spoils  the  pictures. 

An  addition  of  ammonia  to  the  paste  prevents  the  latter  from 
turning  acid.  To  make  starch  paste,  stir  solid  starch  with  an  equal 
quantity  of  water  to  a  thin  paste,  then  pour  into  it  boiling  water, 
stirring  continually  until  you  can  feel  that  it  suddenly  becomes  thick. 
The  operation  can  be  reversed,  the  starch  can  be  poured  into  the  boil- 
ing water  until  it  becomes  thick.  The  paste  still  contains  lumps, 
which  are  removed  by  pressing  the  warm  mass  through  a  piece  of 
muslin.  Mounting  requires  practice,  but  the  necessary  skill  is  easily 
acquired.  Many  operators  use  a  solution  of  gelatin  for  mounting, 
but  I  do  not  find  it  as  convenient  as  common  paste.  The  mounted 
pictures  are  left  to  dry.    When  the  mounts  have  not  been  sized  it  is 


*  By  a  guide  a  il  right  angle,"  L>  is  meant. — Translator. 


188 


THE  PRACTICE  OF  PHOTOGRAPHY. 


best  to  place  them  between  blotting-papers  and  boards,  as  it  facilitates 
the  rolling.  The  rolling  gives  smoothness  to  the  pictures.  The  roll- 
ing presses  used  for  this  purpose  are  generally  imperfect  in  construc- 
tion.   The  price  is  so  low  that  little  can  be  expected. 

The  press  consists  of  a  steel  plate*  (Fig.  72),  on  which  the  mounted 
picture,  with  the  picture-side  downwards,  is  placed ;  it  is  pushed  be- 
tween parallel  cylinders,  a,  b ;  parallelism  is  secured  by  the  screws,  K. 
Before  placing  the  plate  between  the  rollers  the  adjustment  is  care- 
fully made  by  examining  the  distance  with  the  eye.  The  plate  is  now 
placed  in  position,  the  rollers  are  screwed  together  by  turning  the 


Fig.  72. 


\  a 

m 


wheel,  g,  and  plate  and  cylinders  are  carefully  cleaned.  To  ascertain 
if  everything  is  clean  and  in  good  working  order  a  piece  of  white 
Bristol  board  is  passed  through.  The  pictures  are  placed  on  the 
plate  perfectly  dry,  otherwise  they  will  stick.  The  retouches  should 
be  laid  on  before  rolling.  For  small  sized  pictures,  small  presses  with 
smooth  rollers  and  without  a  plate  have  been  made ;  they  are  very 
convenient. 

Large  pictures  should  be  as  even  as  possible  previous  to  being 

*  In  order  to  show  the  cylinder  and  cog-wheels  the  plate  has  been  omitted 
in  the  illustration. 


GELATINIZING  OF  PHOTOGRAPHS. 


189 


placed  in  the  press;  a  slight  moistening  of  the  mount  previous  to 
placing  the  picture  on  it,  and  drying  between  blotting-paper  under 
pressure,  will  secure  this  result.  If  the  pictures  have  curved  very- 
much  by  drying,  it  is  well  to  press  them  straight  with  the  backs  over 
the  sharp  edge  of  a  table  repeatedly  until  they  remain  flat. 

In  the  Excelsior  Press  of  the  Scovill  Manufacturing  Company, 
N.  Y.,  which  is  in  common  use  in  America,  the  steel  plate  is  dispensed 
with.  This  reduces  the  cost  very  much,  and  makes  a  very  desirable 
press.  The  gearing  shown  in  the  figure  below  makes  the  adjustment 
very  easy,  and  it  is  a  very  good  press. 


Fig.  73. 


Lately  Mr.  Entrekin  has  introduced  a  machine,  in  which  the  plate 
can  be  heated.  Pictures  pressed  with  a  hot  plate  receive  an  extraordi- 
nary gloss,  more  so,  and  nicer  than  with  wax.  In  Germany  a  method  is 
in.  vogue,  whereby  pictures  are  made  very  glossy  with  gelatin  ;  such 
pictures  are  called  enamelled  or  glace  pictures. 


SECTION  III. 

GELATINIZING  OF  PHOTOGRAPHS,  AND  ENAMEL  PICTURES. 

If  a  finished  paper  photograph  is  moistened  with  the  tongue  it  as- 
sumes an  unusual  brilliancy,  the  cause  being  that  one  part  of  the 
picture  being  beneath  the  surface,  is  only  visible  when  the  surface  is 
made  transparent.  This  transparency  disappears  as  soon  as  the  paper 
dries.  The  transparency  can  be  made  more  lasting  by  rubbing  with 
cerate,  to  be  had  at  the  dealers,  or  with  an  emulsion  consisting  of  1  part 


190 


THE  PRACTICE  OF  PHOTOGRAPHY. 


of  white  wax  in  100  parts  of  ether;  this  also  soon  becomes  dull,  it  pene- 
trating into  the  paper.  A  very  pretty  method,  although  not  adapted 
for  vignettes,  is  to  burnish  them  with  a  press  in  which  the  plate  is 
heated.  Instead  of  this,  the  method  of  gelatiuizing,  which  we  will 
describe  below,  has  become  in  vogue.  For  this,  two  warming-bot- 
tles,* made  of  tin  plate,  which  have  the  shape  of  a  right-angled  box, 
are  requisite  (one  of  12"  square,  and  2¥'  in  height,  the  other  of  9  X  3" 
square,  also  2¥'  height)  having  on  one  end  a  small  tube  for  filling. 
The  large  one  is  used  to  heat  the  collodionized  plate  previously  to 
using  the  smaller  one  as  a  warm  support  while  gelatinizing.  The  pur- 
pose of  these  bottles  is  to  keep  the  prepared  collodion  plates  slightly 
warm  until  ready  for  the  operation,  to  prevent  any  interruption  while 
working  the  gelatin  solution,  which  is  apt  to  cause  blisters.  Small 
plates  of  plate-glass,  size  5  X  3J",  are  necessary,  and  are  coated  with 
plain  collodion  and  dried.  Before  commencing  both  bottles  are  half 
filled  with  water.  On  the  upper  surface  place  a  piece  of  card  of  cor- 
responding size;  this  is  done  for  two  reasons:  first,  to  prevent  the  glass 
plates  from  touching  the  tin ;  second,  to  keep  the  gelatin  clean,  which 
is  apt  to  drop  out  during  the  operation,  for  further  use.  The  gelatin 
solution  consists  of  1  part  of  clean  gelatin  and  8  parts  of  water.  The 
gelatin  is  cut  into  small  pieces,  put  in  a  stone-ware  cooking-jar,  cold 
water  poured  on,  and  dissolved,  continually  stirring  with  a  glass  rod, 
with  a  gentle  heat ;  afterwards  strain  through  a  close  linen  into  the 
gelatin  apparatus.  Cartes  de  visite  and  cabinet  photographs  are 
usually  mounted  on  cards  with  name  of  the  firm  on  the  back,  and  in 
the  usual  manner,  touched,  pressed,  and  finished.  Those  intended  for 
gelatinizing  are  only  discerned  from  the  others  by  being  somewhat 
larger.  For  subsequent  trimming,  the  size  of  the  cards  is  marked 
with  a  lithographic  square.  A  very  frequent  cause  of  failure  in 
gelatinizing  cartes  de  visite,  is  that  the  edges,  during  the  operation, 
or  later,  in  taking  off  the  glass,  are  injured;  by  using  larger  cards  the 
latter  can  be  avoided.  To  avoid  the  first,  a  simple  method  is  given 
below. 

All  preparations  being  in  readiness,  operate  as  follows  :  Several  col- 
lodionized plates  are  placed  on  the  large  warming-bottle,  film-side  up, 
for  a  previous  warming.  One  being  placed  on  the  smaller  one,  a  carte 
de  visite  is  dipped  in  the  warm  gelatin  solution  (face  upwards),  and 
after  a  short  pause  picked  out  in  such  a  manner  (horizontal,  if  possible), 
that  a  sufficient  quantity  covers  the  picture.  The  picture  is  now  laid 
with  the  long  edge  on  the  edge  of  the  plate  nearest  the  operator,  at 


*  A  warming-box  would  be  more  appropriate. 


CARE  OF  THE  NEGATIVE. 


191 


the  same  moment  leaving  the  whole  picture  come  down  on  the  plate. 
Hold  with  two  fingers  of  the  left  hand,  the  short  edge  lying  nearest,  and 
rub  the  back  with  the  middle  finger  of  the  right,  in  short  regular 
strokes,  commencing  at  the  furthest  edge,  over  the  whole  picture.  Six  to 
seven  strokes  made  with  the  breadth  of  the  last  joint  of  the  middle 
finger  with  a  slight  pressure,  are  sufficient  to  remove  all  superfluous 
gelatin  solution,  at  the  same  time  any  bubbles  contained  therein.  In 
making  the  strokes,  care  must  be  taken  that  between  the  strokes  no 
space  is  left  untouched,  as  blisters  will  then  surely  remain.  The 
gelatin  must  in  a  certain  manner  be  forced  from  the  front  edge  to  the 
opposite.  Herewith,  as  already  mentioned,  all  bubbles  are  certainly 
removed. 

The  backs  of  the  pictures  are  then  cleaned  of  the  gelatin  solution 
remaining  with  a  sponge  dipped  in  warm  water,  and  the  plate  with  the 
glass  side  up  is  placed  on  a  thoroughly  wet  and  flat  piece  of  flannel 
until  the  gelatin  has  set.  This  is  the  method  mentioned  above  to 
prevent  edges  coming  off  directly  after  gelatinizing.  If  the  card  side 
of  the  gelatinized  plate  is  laid  on  top,  they  would  dry  very  rapidly, 
causing  shrinking,  and  a  sure  coming  off  at  the  edges.  Being  done 
with  gelatinizing,  all  plates  can  be  turned  and  dried  in  an  ordinary 
room  temperature.  The  best  time  for  gelatinizing  is  in  the  evening ; 
the  next  day,  about  8  or  9  o'clock,  the  pictures  can  be  removed  from 
the  glass.  The  removal  will  be  difficult  if  the  foregoing  manipu- 
lations have  not  been  closely  followed  or  indifferently.  The  pictures 
are  often  cameoed.  For  this  purpose  cameo  presses  are  used,  in  which 
the  picture  is  laid  and  pressed.    Chute's  is  the  best  form. 

SECTION  IV. 

CARE  OF  THE  UTENSILS  AND  CHEMICALS  IN  THE  POSITIVE  PROCESS. 

Care  of  the  Negative. 

Negatives  are  the  photographic  printing  plates,  and  the  photogra- 
pher has  to  bestow  care  on  their  preservation  in  proportion  to  the 
number  of  prints  which  he  expects  to  take  from  them  ;  this  becomes 
the  more  difficult,  as  on  the  one  hand  the  material  is  the  most  fragile 
in  existence ;  on  the  other  hand,  the  printing  surface,  i.  e.,  the  var- 
nished collodion  film,  offers,  when  compared  with  a  lithographic  stone 
or  a  copper-plate,  a  very  soft  and  easily  injured  surface.  When  we 
add  to  this  the  almost  indispensable  negative  retouch,  which,  in  the 
shape  of  india-ink  or  oil  paint,  is  placed  on  the  glass  or  on  the  var- 


192 


THE  PRACTICE  OF  PHOTOGRAPHY. 


nished  surface,  and  which  can  be  rubbed  off  with  the  finger,  and 
when  we  consider  further,  that  for  the  prints  a  paper  is  used,  impreg- 
nated with  one  of  the  most  caustic  substances — nitrate  of  silver — 
which,  of  course,  exercises  its  influence  on  the  varnish,  we  cannot  help 
feeling  surprised  that  a  negative  actually  lasts  as  long  as  it  does.  Let 
any  one  touch  a  negative,  from  which  a  dozen  prints  have  been  made, 
with  the  point  of  the  tongue,  and  he  will  be  surprised  how  strongly  it 
tastes  of  nitrate  of  silver. 

This  circumstance  alone  indicates  chemical,  changes  in  the  negative 
during  printing.  The  silver  salt  is  partly  absorbed  by  the  varnish, 
the  latter  becomes  colored  by  the  light — generally  yellowish — and, 
with  a  large  edition,  the  last  prints  appear  harder  than  the  first  im- 
pressions. 

With  a  weak  negative  this  may  sometimes  be  an  advantage. 
Another  change,  but  a  much  more  dangerous  one,  is  caused  by  mois- 
ture. Mr.  Stiehm  communicated  to  the  Mittheilungen  the  result  of 
an  experiment  which  showed,  in  a  characteristic  manner,  the  influence 
of  moisture.  He  placed  damp  blotting-paper  on  a  negative,  and 
twelve  hours  afterwards  it  showed  cracks.  These  cracks,  unfortu- 
nately, appear  too  often  on  their  own  account,  and  spoil  many  a  beau- 
tiful negative.  They  happen  most  frequently  with  plate-glasses,  and 
we  once  heard  the  remark  that  they  only  happen  with  them.  My  ex- 
perience teaches  me,  however,  that  other  glass  is  equally  liable  to  this 
fatality,  although  not  so  frequently,  and  I  feel  convinced  that  mois- 
ture is  the  main  cause  of  its  origin.  It  has  happened  to  me,  that  of  a 
number  of  negatives,  which  were  made  at  the  same  time  and  under 
similar  circumstances,  some,  which  had  been  handed  to  the  printer, 
became  cracked,  while  the  others,  which  remained  undisturbed  in  the 
closet,  showed  no  such  tendency.  And  here  the  fact  established  itself 
that  a  negative  which  had  been  kept  in  a  very  damp  place  showed 
this  tendency  soonest ;  and,  further,  that  gross  carelessness  of  the 
printer,  who  had  employed  imperfectly  dried  paper,  caused  the  balance 
of  the  injury.  Too  much  license  is  given  to  the  printer.  In  no  place 
is  strict  surveillance  more  necessary  than  here  ;  they  hold  in  their  pos- 
session the  treasure  of  the  photographer,  and  how  do  they  treat  it?  I 
have  noticed  myself  that  in  printing-frames,  which  were  removed  at 
the  beginning  of  a  shower,  the  pad  at  the  back  of  the  negative  had 
become  moistened,  and  still  the  printer  did  not  consider  it  worth  his 
while  to  replace  it  by  a  dry  one. 

The  consequences  of  such  carelessness  are  easily  imagined.  They 
may  not  manifest  themselves  at  once,  but  after  the  twentieth  or  for- 
tieth impression  the  varnish  will  show  cracks.    Most  proprietors  have 


CARE  OF  THE  NEGATIVE. 


193 


no  idea  how  many  negatives  are  totally  destroyed  by  grains  of  sand 
insinuating  themselves  into  the  printing-frame ;  or  how  many  films 
are  scratched  by  careless  handling. 

These  circumstances  explain  the  variable  permanency  of  the  nega- 
tives in  our  galleries. 

Some  photographers  preserve  their  negatives  in  plate  boxes;  this 
method  can  only  be  recommended  when  the  boxes  are  made  of  dry 
and  well-varnished  wood.  It  is  much  better  to  keep  them  in  airy 
closets  in  a  dry  room,  and  I  consider  it  as  advantageous  that  the 
closets  are  removed  a  little  from  the  wall,  so  as  to  permit  a  current  of 
air  to  circulate  around  them. 

I  have  noticed  that  leakage  in  the  roof  admitted  water  into  the 
negative  storeroom ;  it  manifested  itself  as  a  damp  streak  along  the 
wall,  which,  while  covered  by  the  closet  containing  the  negatives,  was 
not  noticed,  until  finally  the  moisture  penetrated  through  the  wooden 
partition  of  the  closet,  and  became  visible.  The  result  was  that  some 
valuable  negatives  were  lost  by  cracking  of  the  film.  I  must  also 
mention  another  characteristic  circumstance.  The  author  noticed 
that  the  plates  which  were  made  in  the  moist  climate  of  Aden  showed 
an  exceedingly  tender  film,  while,  on  the  other  hand,  those  that  were 
taken  in  the  desert  showed  no  such  delicacy.  In  the  production  of 
the  negative,  moisture  plays  an  important  role  as  regards  permanency. 
The  author's  experience  leads  him  to  reject  a  caoutchouc  solution  pre- 
vious to  varnishing  as  unreliable;  on  the  contrary,  it  makes  the  film 
more  tender. 

It  has  been  recommended  to  treat  the  negative  to  a  solution  of  gum 
Arabic,  1 :  30,  previous  to  varnishing.  But  such  plates  are  not  in- 
sured against  cracking  either. 

The  restoration  of  cracked  negatives  offers  other  difficulties ;  the 
method  which  has  frequently  been  suggested,  of  exposing  the  film  to 
the  vapors  of  alcohol  and  ether,  by  placing  it  on  a  dish  containing 
these  two  fluids,  has  been  frequently  recommended ;  but  it  is  not  always 
successful.  The  cracks  do  not  always  bear  the  same  character ;  many 
of  them  are  thrown  up,  like  the  burrows  of  a  mole. 

The  latter  will  disappear  almost  completely  when  we  place  the 
negative  over  a  dish  containing  a  little  alcohol.  The  varnish  becomes 
soft  in  twenty-four  hours,  and  the  outlines  of  the  cracks  coalesce. 

The  negative  is  warmed  afterwards  in  order  to  harden  the  varnish. 

Another  kind  of  cracks  are  the  so-called  hard  lines ;  they  are  not 
elevated,  but  depressed ;  they  can  be  partially  removed  by  rubbing 
them  over  with  gray  silver  powder  (silver  precipitated  by  sulphate  of 
iron). 

12 


194  THE  PRACTICE  OF  PHOTOGRAPHY. 

Some  will  disappear  by  pressure  with  the  finger-nails ;  but  the  vapors 
of  alcohol  will  not  obliterate  them.  Warming  of  the  plate  will  some- 
times remove  them  completely ;  but  unfortunately  they  will  reappear 
after  awhile. 

Under  such  circumstances  a  process  which  enables  us  to  multiply 
negatives  becomes  for  the  photographer  absolutely  invaluable.  We 

will  consider  such  a  method  in  one  of  the  subsequent  chapters. 

* 

THE  CARE  OF  THE  PAPER. 

The  photographic  paper,  which  is  stored  in  a  dry  place,  will  keep 
for  a  considerable  period.  It  seems  almost  as  if  albumen  paper  which 
has  been  on  hand  for  some  time  would  give  better  results  than  fresh 
paper. 

In  the  albumen  film  itself  changes  take  place  in  course  of  time ; 
gases  are  developed,  and,  sometimes,  the  products  of  decomposition 
may  affect  the  process  injuriously.  It  is,  for  instance,  an  established 
fact  that  good  albumen  paper,  which  had  been  sent  to  America  in 
soldered  tin  boxes,  on  its  arrival  proved  worthless ;  but  after  being 
exposed  to  the  air  for  some  time  it  yielded  good  results.  This  circum- 
stance seems  to  make  the  keeping  of  albumen  paper  in  an  airy  room 
advisable. 

Another  circumstance  which  influences  the  paper  very  much,  is  the 
state  of  dryness  of  the  albumen  surface. 

When  the  latter  is  very  dry,  for  instance,  in  the  heat  of  the  summer, 
we  notice  that  the  paper  repels  the  bath  as  if  it  was  greasy,  and  be- 
comes covered  with  small  blisters ;  when  placed  in  the  wash-water, 
on  leaving  the  fixing  solution,  these  blisters  sometimes  disappear  again, 
and  at  other  times  they  break  and  spoil  the  picture. 

They  can  be  avoided  by  placing  the  paper  twenty-four  hours  before 
use  in  a  damp  cool  place,  a  cellar,  for  instance. 

If  blisters  still  make  their  appearance,  the  paper  should  not  be 
placed  in  water  at  once  after  leaving  the  fixing  solution,  but  should 
be  immersed  in  a  solution  of  hypo  twice  as  weak  as  the  fixing  bath, 
next  in  one  four  times  as  weak,  and  finally  washed  in  water. 

The  abovementioned  facts  demonstrate  that  the  paper  should  possess 
a  certain  degree  of  moisture  in  order  to  secure  good  results. 

This  refers  to  silvered  paper  also.  When  we  place  silvered  paper 
in  a  box  with  chloride  of  calcium,  the  latter  will  deprive  it  of  all  its 
moisture ;  it  will  keep  white  for  a  long  time,  but  it  will  fail  to  give 
satisfactory  results. 

The  turning  yellow  of  silvered  paper  is  an  evil  which  in  summer- 


CARE  OF  THE  POSITIVE  SILVER  BATH. 


195 


time  gives  much  trouble  to  the  photographer ;  it  shows  itself  particu- 
larly with  papers  that  have  been  made  with  old  and  fermented  albu- 
men ;  the  yellow  color  disappears  in  the  gold  and  fixing  baths  partly, 
particularly  when  we  add  to  the  latter  a  one-thousandth  part  of  cyan- 
ide of  potassium.    Still  pictures  taken  on  such  paper  lack  brilliancy. 

Silvered  paper  will  keep  white  longer,  if  copperplate  paper,  previ- 
ously soaked  in  bicarbonate  of  soda  and  dried,  is  placed  back  of  it. 
Oil  cloth  acts  similarly,  probably  in  keeping  off  the  gases  formed  in  the 
printing  pad,  which  have  a  reducing  action. 

THE  CARE  OF  THE  POSITIVE  SILVER  BATH. 

The  positive  bath  is  not  liable  to  near  as  many  accidents  as  the 
negative  bath.  Microscopic  quantities  of  organic  substances  or  acids 
will  affect  the  latter  to  some  extent,  and  sometimes  make  it  useless. 
The  positive  bath  is  not  affected  by  impurities  in  such  small  quanti- 
ties. It  is  evident  that  the  impurities  must  increase  with  every  addi- 
tional sheet  of  paper,  as  the  nitrates  which  are  formed  by  double  de- 
composition pass  into  it;  still  they  do  not  seem  to  hurt,  but  on  the 
contrary  exert  a  beneficial  influence,  as  the  absorption  of  silver,  from 
an  old  bath  is  less  than  from  a  new  one. 

Organic  impurities  also  pass  from  the  paper  into  the  bath.  The 
condition  of  the  albumen  used  on  the  paper  is  quite  variable ;  on  some 
papers  it  is  laid  on  fresh,  while  in  other  cases  it  is  first  subjected  to 
fermentation.  Its  chemical  properties  are  not  the  same,  and  so  it 
happens  that  some  papers  impart  so  much  organic  matter  to  the 
bath  that  after  a  few  sheets  have  been  silvered  it  will  turn  brown. 
In  this  state  it  is  unfit  for  use,  as  the  paper  cannot  be  evenly  sensi- 
tized upon  it. 

Fortunately  we  possess  in  the  permanganate  of  potash  a  remedy 
which  will  restore  a  bath  so  discolored  instantly. 

The  method  is  the  same  as  described  above,  when  speaking  of  the 
negative  bath. 

Formerly  a  bath  which  had  turned  brown,  was  exposed  to  sun- 
light ;  this  led  to  the  same  result,  but  the  process  was  much  slower. 

Besides  its  strength,  we  have  to  consider  the  reaction  of  the  bath. 
A  neutral  bath  is  in  the  most  favorable  condition. 

But  it  happens  frequently  that  a  bath,  which  is  neutral  when  new, 
turns  gradually  acid,  when  the  albumen  paper  has  an  acid  reaction ; 
in  this  case  the  bath  is  apt  to  turn  brown,  and  the  pictures  are  gray 
and  weak.  Testing  with  litmus-paper,  and  the  addition  of  a  little 
solution  of  soda,  will  easily  remedy  this.    To  keep  a  bath  neutral,  the 


196 


THE  PRACTICE  OF  PHOTOGRAPHY. 


addition  of  the  carbonate  of  the  oxide  of  silver  is  very  good ;  it  is  put 
into  the  stock-bottle ;  it  is  easily  made  by  adding  a  little  carbonate  of 
soda  to  the  bath.  Some  papers  will  stand  an  alkaline  silver  bath 
without  detriment ;  these  papers  generally  contain  a  certain  quantity 
of  free  acid. 

Some  manufacturers  intentionally  add  organic  acids  to  the  albumen, 
for  instance,  citric  acid ;  it  produces  a  more  reddish  tone,  and  keeps 
the  silvered  surface  white  for  a  longer  time. 

I  do  not  think  that  such  additions  are  advisable.  A  portion  of  the 
acid  enters  the  bath,  and  seems  to  impart  to  it  a  red  color  under  cer- 
tain circumstances. 

A  bath  with  an  alkaline  reaction  sometimes  attacks  a  film  which  is 
easily  soluble.  A  weak  acid,  such  as  acetic  acid,*  is  the  best  for  neu- 
tralizing it. 

Another  change  in  the  bath  is  produced  by  the  loss  of  the  silver 
salt. 

With  a  very  strong  bath  (12 i  per  cent,  and  more)  this  circumstance 
does  not  amount  to  much,  for  even  when  the  amount  of  silver  has  been 
reduced  as  low  as  5  per  cent.,  the  bath  will  work  well,  provided  the 
paper  is  of  good  quality. 

Otherwise  the  deficiency  of  silver  soon  manifests  itself  by  the  weak- 
ness of  the  prints.  The  shadows  do  not  appear  vigorous ;  the  lights  are 
gray,  and  the  picture  is  monotonous;  sometimes  it  will  cause  the  peel- 
ing of  the  albumen  film.  It  is  therefore  absolutely  necessary  that  the 
bath  should  be  tested  from  time  to  time,  and  fresh  silver  salt  added 
according  to  circumstances. 

For  this  purpose  instruments  called  hydrometers  are  used  ;  they  are 
placed  in  the  bath  and  sink  into  the  liquid  according  to  the  specific 
gravity  of  the  same  ;  they  are  provided  with  a  scale  divided  in  degrees, 
and  by  noticing  the  degree  indicated  by  the  surface  line  of  the  liquid 
in  which  the  hydrometer  floats,  the  percentage  of  silver  salt  contained 
in  it  can  be  ascertained  by  consulting  a  properly  prepared  table  in 
which  the  degrees  of  the  hydrometer  are  converted  into  per  cen-ts  of 
silver. 

If  the  indications  of  this  instrument  were  reliable  but  little  objection 
could  be  raised  against  its  use ;  but  it  is  well  known  that  the  indica- 
tions are  influenced  in  the  highest  degree  by  the  presence  of  alcohol, 
ether,  acetic  acid,  and  different  salts,  to  such  an  extent  that  the  test 


*  According  to  a  statement  by  Mr.  England,  a  brown  batb  is  restored  by 
boiling  it  from  10  to  15  minutes.  The  organic  matter  separates  with  a  part 
of  the  silver. 


CARE  OF  THE  POSITIVE  SILVER  BATH.  197 


not  only  becomes  useless,  but  even  worse,  because  the  wrong  indica- 
tions mislead,  deceive,  and  produce  errors  of  the  most  fatal  kind. 
These  experiences  make  the  introduction  of  a  reliable  silver  tester  a 
necessity. 

Gay-Lussac  gave  us  such  a  method  in  the  so-called  triturating  pro- 
cess with  chloride  of  sodium.  A  solution  of  chloride  of  sodium  of  a 
given  strength  is  added  to  a  silver  solution  until  no  further  precipitate 
of  chloride  of  silver  takes  place.  The  quantity  of  the  chloride  of 
sodium  solution  necessary  to  precipitate  all  the  silver  determines  the 
quantity  of  the  latter.  Unfortunately  this  method  has  a  drawback  ; 
the  cloudy  appearance  of  the  liquid  makes  it  very  difficult  to  ascer- 
tain the  precise  moment  when  the  precipitation  of  chloride  of  silver 
ceases.    The  following  method  of  the  author  is  free  from  this  error. 

This  method  is  based  on  the  peculiar  action  of  iodide  of  potassium 
on  solutions  of  nitrate  of  silver  on  the  one  hand,  and  nitric  acid  on 
the  other  hand.  When  iodide  of  potassium  is  added  to  a  solution  of 
nitrate  of  silver,  a  precipitate  of  yellow  iodide  of  silver  will  be  formed  ; 
when  iodide  of  potassium  is  added  to  a  thin  solution  of  starch  paste 
and  nitric  acid,  containing  a  small  quantity  of  nitrous  acid,  iodine  will 
at  once  be  set  free,  which  imparts  to  all  of  the  liquid  a  deep  blue 
color. 

When  we  add  a  solution  of  iodide  of  potassium  to  a  mixture  of  the 
solutions  of  nitrate  of  silver,  nitrous  acid,  and  starch,  the  two  processes 
will  take  place  simultaneously ;  iodide  of  silver  will  be  formed  as  a 
precipitate,  and  free  iodine,  which  in  the  presence  of  starch  paste  im- 
parts to  the  liquid  a  blue  color.  But  so  long  as  a  free  salt  of  silver  is 
present  in  the  solution,  this  blue  color  will  disappear  at  once  on  agita- 
tion, and  the  liquid  will  assume  a  pure  yellow  color.  When  we  con- 
tinue to  add  the  solution  of  iodide  of  potassium  drop  by  drop,  we  will 
soon  arrive  at  a  point  where  the  blue  color  no  longer  disappears  on 
shaking  the  liquid,  but  remains  permanent ;  this  indicates  that  all  the 
free  salt  of  silver  has  been  precipitated,  and  from  the  quantity  of  iodide  of 
potassium  solution  which  was  necessary  to  produce  this  result,  it  is  easy 
to  determine  the  quantity  of  silver  which  has  been  precipitated.  The 
point  when  all  the  silver  has  been  precipitated  is  ascertained  by  the 
blue  color,  with  surprising  exactness ;  a  single  drop  of  iodide  of  potas- 
sium in  excess  suffices  to  give  to  all  the  liquid  an  intense  and  perma- 
nent blue  color.  (When  iodide  of  silver  is  present  in  large  quantities 
the  color  will  be  more  green  than  blue.) 

To  employ  this  method  practically,  a  solution  of  iodide  of  potassium, 
which  contains  in  1023.4  cubic  centimetres  exactly  10  grammes 
chemically  pure  dried  iodide  of  potassium,  is  prepared.    One  hundred 


198 


THE  PRACTICE  OF  PHOTOGRAPHY. 


cubic  centimetres  of  this  solution  will  precipitate  exactly  1  gramme 
of  nitrate  of  silver ;  hence,  when  we  take  for  a  test  1  cubic  centimetre 
of  silver  solution,  each  cubic  centimetre  of  iodide  of  potassium  solution 
will  indicate  one  per  cent,  of  silver  salt. 

This  solution  is  carefully  poured  into  a  Mohr's  spring  compressor 


Fig.  74. 


burette,*  avoiding  air-bubbles  (the  burette  is  divided  into  -J  cubic  cen- 
timetres). The  burette  is  placed  into  the  holder,  8  (Fig.  74) ;  the 
spring  compressor,  h,  is  opened  by  pressing  the  button,  1c,  and  the  liquid 
is  allowed  to  run  out  until  the  lower  curve  of  the  surface  of  the  liquid 
touches  the  point  0  (zero).  It  is  necessary  that  the  spring  should  at 
first  be  opened  to  the  full  extent,  in  order  to  expel  the  air  and  old 
solution  which  may  have  collected  in  the  lower  part  of  the  tube.  This 
must  not  be  overlooked. 

When  this  has  been  done,  the  cleaned  and  dried  pipette,  p,  is 
dipped  into  the  solution  of  silver  which  is  to  be  tested  ;f  the  air  is 


*  These  spring  compressors  are  very  convenient ;  the  operator  can  at  his 
pleasure  allow  the  liquid  to  run  out  drop  by  drop  or  in  a  stream. 

f  It  is  self-evident  that  the  pipette  must  be  perfectly  clean  and  free  from 
old  solution,  otherwise  it  would  mix  with  the  new  solution,  and  change  its 


CARE  OF  THE  POSITIVE  SILVER  BATH. 


199 


sucked  out  with  the  mouth,  and  when  the  tube  is  nearly  filled,  the 
upper  opening  is  quickly  closed  with  the  dry  index  finger ,  the  pipette 
is  taken  out  of  the  solution,  and  by  lifting  the  finger  gently  the  fluid 
is  allowed  to  run  out  until  it  reaches  the  point  i.  The  lower  end  of 
the  pipette,  which  holds  now  exactly  one  cubic  centimetre,  is  held 
against  the  side  of  the  glass  G;  the  fluid  is  forced  into  the  glass  by 
blowing  in  the  upper  end  of  the  pipette.  Instead  of  the  glass  a  test- 
tube  may  be  used  ;  the  latter  is  more  convenient  for  shaking.  (The 
small  remnant  of  the  fluid  which  may  remain  in  the  point  of  the 
pipette  is  of  no  account.)  Afterwards  add  one  drop  of  nitric  acid  and 
about  one  drop  of  a  solution  of  3  parts  nitrite  of  potassium  (not  nitrate) 
in  100  parts  of  water ;  finally  10  to  15  drops  of  starch  solution*  are 
added.  Now  the  test  may  commence.  The  burette  should  be  ex- 
amined once  more,  to  see  that  the  exact  quantity  of  fluid  is  contained 
in  it.  The  glass  is  lifted  up  high  with  the  left  hand.  The  spring 
compressor  is  opened  carefully  and  a  few  drops  are  allowed  to  flow 
into  the  glass ;  when  the  silver  solution  is  strong,  a  yellow  precipitate 
will  be  formed  at  first,  which  will  afterwards  change  to  blue ;  when 
the  solution  of  silver  is  weak,  the  blue  color  will  show  itself  at  once, 
but  will  disappear  again  on  shaking  the  glass.  In  the  former  case, 
the  iodide  of  potassium  solution  may  be  added  more  freely ;  in  the 
latter  case  more  caution  should  be  exercised.  The  glass,  a,  should  be 
constantly  shaken  to  mix  the  fluid  thoroughly. 

Finally  the  blue  color  will  disappear  more  slowly ;  great  care  is 
now  necessary,  as  a  single  drop  may  suffice  to  produce  a  blue  or  green 
color,  which  will  not  disappear  again  on  shaking.  The  spring  com- 
pressor is  now  closed,  and  the  height  of  the  fluid  is  read  off  the  scale ; 
when  this  indicates,  for  instance,  7f ;  then  the  silver  solution  contains 
7f  per  cent.,  or  in  100  cubic  centimetres  7f  grammes  of  silver.  It  is 
not  at  all  difficult  to  observe  one-tenth  of  one  per  cent,  on  the  scale. 
Those  who  are  not  accustomed  to  work  with  burette  and  pipette  will 
handle  them  at  first  rather  awkwardly ;  but  a  little  practice  will  soon 
give  them  the  necessary  confidence. 

With  strong  silver  solutions  it  is  advisable  to  add,  near  the  close  of 
the  operation,  a  few  drops  of  starch  solution,  particularly  when  the 
color  is  not  very  decided;  with  brown  positive  baths  the  color  is 


character.  In  practice  it  is  sufficient  to  fill  the  pipette,  empty  the  contents, 
and  fill  it  again;  by  repeating  this  operation  twice  or  three  times,  the  solu- 
tion will  be  clean  enough  for  all  practical  purposes. 

*  To  make  the  starch  solution,  put  a  pinch  of  starch-powder  in  a  test-tube, 
fill  with  water,  shake,  and  boil.    The  solution  must  be  cooled  before  using. 


200 


THE  PRACTICE  OP  PHOTOGRAPHY. 


always  somewhat  dirty ;  still,  with  a  little  extra  care,  the  determina- 
tion is  not  difficult.* 

When  with  pure  silver  solutions  the  blue  color  appears  dirty  at  the 
start,  or  not  at  all,  then  the  starch  paste  is  spoiled,  or  the  nitric  acid 
does  not  act.  The  former  is  easily  made  again  ;  the  latter  will  act 
when  a  few  pieces  of  sulphate  of  iron  are  added  (see  below).  If  the 
operation  should  fail  from  the  above  reasons,  or  from  want  of  skill  of 
the  operator,  it  is  very  easy  to  repeat  it. 

The  burette  and  the  iodide  of  potassium  solution  should  be  closed 
with  well-fitting  corks  when  not  in  use.  A  pound  of  iodide  of  potas- 
sium solution  will,  according  to  the  strength  of  the  solutions  to  be 
tested,  suffice  for  from  30  to  50  tests. 


It  is  a  general  complaint  amongst  photographers  that  some  papers 
turn  yellow  very  rapidly  after  they  have  been  sensitized.  A  positive 
remedy  for  this  evil  has  not  been  found  as  yet,  but  it  is  certain  that 
it  can  be  partially  obviated. 

1.  By  keeping  the  paper  in  a  very  dry  place.  Drying  boxes  *and 
tin  cases  with  chloride  of  calcium  have  been  recommended ;  but  I 
must  caution  against  their  use ;  they  preserve  the  paper,  but  the 
paper  prints  badly ;  the  cause  of  it  is  that  the  printing  process — which 
is  a  chemical  decomposition — can  only  take  place  in  a  normal  manner 
in  the  presence  of  a  certain  quantity  of  moisture. 

2.  By  placing  at  the  back  of  the  sensitive  paper,  in  the  printing- 
frame,  a  piece  of  waxed  paper.  In  the  printing  process,  gases  are  de- 
veloped which  exercise  a  reducing  influence ;  these  are  absorbed  by 
the  pad  (consisting  generally  of  felt  or  blotting-paper),  and  cause  the 
paper  to  turn  yellow  rapidly.  A  piece  of  wax  paper  will  prevent 
this. 

3.  In  order  to  make  the  silvered  albumen  paper  more  permanent, 
the  addition  of  citric  acid  has  been  recommended. 

Ost  uses  the  following  bath  : 


*  For  strong  solutions  (positive  bath)  one-half  cubic  centimetre  is  sufficient 
for  a  trial.  But  the  degrees  of  the  burette  which  are  obtained  must  be  mul- 
tiplied by  two. 


THE  CARE  OF  THE  SENSITIZED  PAPER. 


Nitrate  of  silver, 
"Water, 
Citric  acid, 
Alcohol,  . 


1  part. 
12  " 
1  » 
1  " 


FAILURES  IN  SILVERING. 


201 


4.  Mr.  Haugk  writes,  that  when  ordinary  albumen  paper  is  washed, 
after  it  has  been  silvered,  and  all  the  free  nitrate  of  silver  is  removed, 
it  will  keep  white  for  a  long  time,  and  by  fuming  it  with  ammonia,  it 
can  be  made  as  sensitive  as  carbonate  of  silver  paper. 

The  author  has  tried  this  process  and  found  that  it  worked  excel- 
lently. 

THE  CARE  OF  THE  TONING  BATH. 

The  toning  bath  is  not  very  permanent ;  this  is  owing  to  the  un- 
stableness  of  the  salts  of  gold.  Alkaline  toning  baths  must  always  be 
made  fresh  immediately  previous  to  using  them.  Acid  toning  baths, 
and  those  containing  rhodan  gold,  will  keep  longer ;  they  should  be 
strengthened  from  time  to  time.  But  here  also  a  freshly  made  bath 
is  preferable. 

The  residues  of  the  toning  bath  are  filled  in  large  bottles  or  jars, 
and  from  time  to  time  a  little  solution  of  sulphate  of  iron  and  hydro- 
chloric acid  are  added;  the  gold  is  precipitated  in  the  form  of  a 
brown  powder,  and  can  be  collected  and  reconverted  into  chloride  of 
gold. 

This  process  is  not  adapted  to  rhodan  gold  baths  or  those  contain- 
ing hyposulphite  of  soda. 

THE  CARE  OF  THE  FIXING  BATH. 

The  fixing  bath  does  not  keep  well ;  it  should  be  frequently  re- 
newed, as  with  prolonged  use  decomposition  will  take  place,  and  sul- 
phate of  silver  is  formed,  which  causes  the  prints  to  turn  yellow. 

SECTION  V. 

FAILURES    IN    THE    POSITIVE  PROCESS. 
1.  FAILURES  IN  SILVERING. 

1.  Blisters  (see  remarks  thereon). 

2.  The  paper  repels  the  silver  solution ;  this  is  caused  by  the  albumen 
being  too  dry  (see  further  remarks  thereon). 

3.  The  silver  solution  hangs  in  drops  in  the  middle  of  the  sheet ; 
this  is  remedied  partly  like  2.  The  drops  can  also  be  removed  with 
blotting-paper. 

4.  The  paper  is  dried  too  much  or  too  little,  printing  in  such  cases 
weak  or  uneven,  or  ruins  the  negative. 


202 


THE  PRACTICE  OF  PHOTOGRAPHY. 


5.  Coloration  of  the  bath  (see  remarks  thereon). 

6.  Gray  dirt  from  careless  skimming  (see  remarks  thereon). 

2.  FAILURES  IN  PRINTING. 

1.  The  picture  appears  flat,  the  shadows  weak,  the  lights  clouded 
and  dim.  Cause :  Acid  silver  bath,  or  old,  or  weakened  silver  bath  ; 
dried  too  rapidly  or  not  enough  (see  above) ;  damp  printing-pads. 
Thin  negatives ;  these  are  printed  under  green  glass,  or  varnish  the 
front  with  a  varnish  containing  dragon's  blood. 

2.  Clouded  lights  are  caused  by  repeated  examination  of  the  prints 
in  the  broad  daylight. 

3.  Yellow  paper,  caused  by  long  printing  (see  Instructions  on 
Printing). 

4.  Brown  streaks.    Cause  :  Kemains  of  fibrin  in  the  albumen. 

5.  The  print  is  partly  not  sharp.  Cause :  Insufficient  contact,  in 
consequence  of  not  enough  pressure  in  the  printing-frame.  The  paper 
becomes  wavy.  This  occurs  when  the  difference  in  the  temperature  in 
the  silvering  and  printing  room  is  too  great.  Eemedy :  Leave  the 
paper  in  the  printing-room  half  an  hour  before  printing. 

3.  FAILURES  IN  WASHING. 

1.  Black  precipitates  are  formed,  from  substances  containing  sul- 
phur in  the  water,  or  the  remains  of  hypo  in  the  dishes,  especially  in 
gutta-percha  ones. 

2.  Brown-black  spots  are  formed  by  touching  with  fingers  full  of, 
or  not  free  from,  hypo. 

4.  FAILURES  IN  TONING. 

1.  The  print  tones  unevenly.  Cause :  Not  enough  toning  solution ; 
insufficient  movement  of  the  prints  while  toning ;  sticking  together 
of  the  prints,  thereby  preventing  the  solution  from  acting  on  them ; 
leaving  the  prints  lay  too  long  before  toning. 

2.  The  prints  will  not  tone.  Cause  :  (a)  The  bath  contains  iodide 
of  silver,  too  much  acid,  or  a  great  quantity  of  foreign  metals  (see 
how  a  positive  bath  is  made  out  of  a  negative  bath).  The  bath  is 
boiled  (after  removing  the  iodide,  by  thinning  it  with  four  or  five  times 
its  volume)  until  dry,  and  fused  gently  for  some  time.  The  acid  will 
evaporate,  and  the  foreign  metals  will  in  a  great  degree  be  reduced ; 
(b)  The  wash-water  is  polluted  with  sulphur-containing  substances, 
(see  above) ;  (c)  There  is  not  enough  gold  in  the  solution ;  (d)  The 
pictures  are  washed  too  much  This  applies  only  in  applying  the  lime 
toning  bath  (see  remarks  thereon). 

3.  The  whites  are  discolored  if  the  toning  is  done  in  too  light  a  place. 


REDUCTION  OF  SILVER  RESIDUES. 


203 


5.  FAILURES  IN  FIXING. 

1.  Streaks  are  formed  in  consequence  of  uneven  immersion  into  the 
fixing  solution,  or  spots,  from  splashiug  on  prints  not  yet  immersed. 

2.  Yellow  spots  (often  only  visible  after  finished)  cause  blisters  on 
the  paper.  Remedy:  Shaking  each  print  separately  in  the  fixing 
solution,  or  brushing  with  a  soft  pencil. 

3.  The  fixing  solution  is  stale,  or  not  sufficient  for  a  large  quantity 
of  pictures.    Yellow  spots  will  show  in  course  of  time. 

4.  Cloudy-looking  spots  are  caused  by  the  prints  not  remaining 
long  enough  in  the  fixing  solution. 

6.  FAILURES  IN  WASHING  AFTER  FIXING. 

1.  The  pictures  become  pock-marked  ;  2.  They  stick  together  on 
the  sides  of  the  washing  tank,  and  turn  rapidly  yellow  in  consequence 
of  the  remaining  hypo ;  3.  They  are  not  sufficiently  washed  (see  test 
for  hypo). 

7.  FAILURES  IN  FINISHING. 

1.  Danger  in  drying  between  blotting-paper ;  defective  card-mounts. 

2.  Faulty  paste ;  accidents  or  failures  in  pressing  and  burnishing. 

SECTION  VI. 

THE  REDUCTION  OF  SILVER  RESIDUES. 

Of  the  large  quantity  of  silver  which  photographers  use,  particu- 
larly in  the  positive  process,  we  find,  according  to  Davanne,  about, 

a.  3  per  cent,  in  the  finished  picture. 

b.  7  per  cent,  in  the  drippings,  filters,  paper  trimmings,  and  in  the 

paper  with  which  wasted  solution  has  been  wiped  up. 

c.  50  to  55  per  cent,  in  the  wash-water  of  the  exposed  paper  in  the 

form  of  a  silver  salt. 

d.  30  to  35  per  cent,  has  been  passed  into  the  fixing  bath. 

e.  5  per  cent,  at  most  in  the  wash-water  of  the  fixed  prints. 

To  recover  these  residues  is  financially  a  matter  of  great  importance. 

Usually  photographers  collect  the  first  wash-water  in  a  barrel,  and 
precipitate  the  silver  with  common  salt.  An  excess  should  be  avoided, 
as  it  will  retard  the  precipitation  of  chloride  of  silver. 


204 


THE  PRACTICE  OF  PHOTOGRAPHY. 


After  twenty-four  hours  the  clear  water  is  drawn  off  the  precipitate, 
and  silver  water  is  collected  again ;  when  this  process  has  been  repeated 
for  months,  the  precipitate  of  chloride  of  silver  is  collected  on  a  cloth, 
washed  with  water,  and  dried. 

The  silver  which  has  been  recovered  from  the  developing  solution 
(negative  process)  may  be  added  to  the  above. 

To  reduce  the  dry  mass  the  melting  process  is  the  most  suitable. 

A  good  Hessian  crucible  is  heated  in  a  furnace  to  a  red  heat,  and 
gradually  the  following  perfectly  dry  mixture  is  introduced : 

Chloride  of  silver  residue,      ....      3  parts. 
Carbonate  of  soda,  free  from  water,  " 

It  is  well  to  rub  the  inside  of  the  crucible  with  chalk  or  white  clay, 
previous  to  heating  it. 

The  smelting  should  be  continued  until  the  whole  mass,  which  at 
first  froths  very  much,  flows  evenly;  it  is  then  allowed  to  cool,  the  cru- 
cible is  broken,  and  the  button  of  silver  is  taken  out. 

Fixing  waters  of  hyposulphite  of  soda  are  collected  separately  in 
large  earthen  jars,  large  enough  to  hold  the  water  of  two  days,  or 
the  fixing  bath  and  the  first  water  after  fixing  of  from  4  to  6  days. 
In  each  jar  a  bright  copper  plate  is  placed,  or  better  still  two  plates 
opposite  to  each  other.  The  metallic  silver  will  collect  on  these  plates 
in  48  hours,  and  can  be  removed  with  a  stiff  brush.  The  precipitate 
which  has  been  brushed  from  the  plates  may  be  taken  out  at  once,  or 
it  may  remain  until  a  sufficient  quantity  has  collected  for  smelting 
purposes ;  at  all  events  after  brushing  off  the  precipitate  sufficient  time 
should  be  allowed  for  it  to  settle. 

When  it  is  removed  from  the  liquid,  it  should  be  filtered  either 
through  linen  or  paper,  according  to  quantity,  and  be  dried  in  the 
open  air  or  on  a  stove. 

After  this  mix 

100  parts  of  the  washed  and  dried  silver  powder, 
50       "     melted  and  powdered  borax, 
25       "  "       "     .    "  saltpetre. 

The  saltpetre  has  to  oxidize  the  particles  of  copper  which  have  been 
removed  by  the  brush.  The  crucible  is  filled  one-third  full  with  the 
mixture,  and  when  the  foaming  has  ceased  it  is  heated  for  about 
twenty  minutes  longer  on  a  brisk  fire ;  the  mixture  is  then  allowed  to 
cool,  and  the  crucible  is  broken. 

The  resulting  metal  contains  some  copper,  but  this  does  not  do  any 


KEDUCTION  OF  SILVER  RESIDUES. 


205 


harm  ;  it  can  be  used  for  producing  the  silver  salt  by  dissolving  it  in 
nitric  acid. 

Papers  containing  silver  should  be  collected  and  burned  ;  the  ashes 
are  collected,  and  when  all  organic  matter  has  been  removed  by  heat, 
a  mixture  should  be  made  of 

100  parts  of  ashes, 
50     "       dry  carbonate  of  soda, 
25      "       quartz  sand. 

The  melting  goes  on  rapidly,  and  the  result  is  a  quantity  of  silver 
varying  from  20  to  60  per  cent.,  according  to  the  composition  of  the 
papers. 

An  important  point  for  America  is  the  method  of  precipitating  the 
waste  silver  water.  As  the  precipitation  is  patented,  another  expe- 
dient has  been  brought  into  requisition,  which  consists  in  the  use  of 
a  galvanic  battery,  which  reduces  the  silver  in  such  water  to  a  metallic 
state.  (See  Philadelphia  Photographer,  report  of  the  German  Photo- 
graphic Society  of  New  York.) 


206 


THE  PKACTICE  OF  PHOTOGRAPHY. 


CHAPTER  VI. 

DIFFERENT  PHOTOGRAPHIC  PROCESSES. 
SECTION  I. 

PERMANENT  SENSITIVE  NEGATIVE  PLATES  (DRY  PLATES). 

The  processes  described  in  Chapter  III,  the  silver  negative  and 
positive  processes,  are  at  present  those  universally  practiced,  and  are 
adapted  to  solve  a  multiplicity  of  photographic  problems.  There 
are  also  beside  these  many  others  but  seldom  used  in  practice,  which  are 
advantageous  under  certain  circumstances,  such  as  easier  and  conve- 
nient working  (like  dry  plates  for  landscapes),  or  the  production  of 
a  peculiar  style  of  picture  (transparent  positive,  pigment  prints, 
porcelain  pictures,  etc),  which  are  often  desired  by  the  public.  The 
most  important  of  these  processes  we  will  describe  in  the  present 
chapter. 

SUMMARY  AND    SUCCESSIVE   OPERATIONS  IN   THE  SILVER-POSITIVE 

PROCESS. 

1.  Preparations. 
Filtering  and  skimming  of  the  silver  bath. 
Cutting  of  the  albumen  paper. 

2.  Operations. 
Sensitizing  in  a  darkened  room. 
Drying  in  a  darkened  room. 
Cleaning  the  negatives. 

Preparing  the  negatives. 

Laying  and  pressing  of  the  sensitive  paper  in  the  printing-frame 
(in  a  darkened  room). 
Exposing, 

Occasional  examination  of  the  prints  during  the  exposure  (in  a 
dark  place). 

Washing  (all  the  prints  in  four  changes  of  water). 

The  negative  process  requires  a  dark-room  for  the  preparation  of 


OPERATIONS  IN  THE  SILVER  -  POSITIVE  PROCESS.  207 


the  sensitive  plates,  which  the  travelling  photographer,  has  not 
always  at  his  disposal.  It  furnishes  wet  plates,. which  dry  rapidly, 
and  after  a  short  time  become  useless.  It  has  been  tried  to  obviate 
this  difficulty  by  making  permanent  sensitive  dry  plates,  which  can 
be  prepared  at  home,  and  carried  along  on  an  excursion.  Such 
plates  should  retain  their  sensitiveness  for  a  long  period,  and  should 
not  require  development  until  after  the  return  home. 

Permanent  sensitive  positive  paper  has  also  been  prepared,  which, 
when  bought  ready  made,  obviates  the  unclean  work  of  silvering, 
and  is  not  liable  to  the  danger  of  turning  yellow  in  the  printing- 
frame. 

Very  great  efforts  have  been  made  to  produce  permanent  dry 
plates  and  permanent  sensitive  papers,  which,  as  regards  certainty 
and  beauty  of  the  results,  should  be  equal  to  the  wet  process.  Every 
day  neAV  dry  processes  and  new  sensitive  papers  make  their  appear- 
ance. It  is  doubtful  which  method  is  the  best.  So  much,  however, 
is1  certain,  that  the  production  of  dry  plates,  as  well  as  sensitive 
paper,  is  still  very  unreliable,  and  in  spite  of  the  greater  expenditure 
of  care  and  time,  which  the  preparation  of  these  bodies  makes  neces- 
sary, success  cannot  be  guaranteed  in  the  same  measure  as  with  the 
wet  process. 

While  in  practicing  the  latter  perfect  cleanliness  is  a  conditio  sine 
qua  non,  it  is  still  more  so  in  the  dry  process. 

The  abovementioned  common  fault  of  negative  plates  getting 
spoiled  by  the  drying  of  the  silver  solution  is  obviated  by  simply 
washing  the  plates  after  silvering.  It  is  best  to  use  distilled  water 
for  this  purpose,  which  must  be  absolutely  pure  and  particularly 
free  from  alkaline  reaction.  We  obtain  in  this  manner,  after  letting 
them  stand  for  a  short  time,  plates  coated  with  a  dry  film  of  yellow 
iodide  of  silver,  which,  when  exposed  and  developed  in  the  manner 
described  below,  will  yield  a  picture.  It  has  been  noticed  that  the 
degree  of  sensitiveness  of  such  plates  is  very  small,  and  an  exposure 
four  times  as  long  as  in  the  wet  process  is  necessary.  The  cause  of 
this  is  the  great  transparency  of  the  dry  plates.  A  plate  saturated 
with  a  solution  of  nitrate  of  silver  absorbs  almost  all  the  actinic 
light  which  falls  upon  it,  while  a  washed  plate  allows  a  considerable 
portion  to  pass  through  it,  which  of  course  is  lost  for  the  formation 
of  the  picture.  It  is,  therefore,  necessary  to  prepare  the  plates  with 
a  strongly  iodized  collodion,  which,  on  account  of  the  large  quantity 
of  salt  contained  in  it,  will  form  a  denser  film  of  iodo-bromide  of 
silver ;  this  absorbs  the  light  more  completely ;  or  else  the  back  of 
the  plates  should  be  covered  with  an  opaque  pigment.    It  should 


208 


THE  PRACTICE  OF  PHOTOGRAPHY. 


further  be  observed,  that  with  such  washed  plates  the  sensitizer  is 
deficient  (i.e.,  the  body  which  imparts  sensitiveness  to  the  slightly 
sensitive  pure  iodide  of  silver),  and  that  from  this  cause  alone  the 
action  on  iodide  of  silver  is  of  less  intensity.  For  this  purpose  it 
has  been  tried  to  replace  the  wet  sensitizer  of  the  silver  salts  by  a 
dry  one.  As  such,  all  bodies  absorbing  iodine  can  be  used.  Particu- 
larly tannin,  gallic  acid,  and  certain  resins  have  been  recommended. 
I  distinguish,  therefore,  amongst  dry  processes,  the  tannin,  resin, 
gallic  acid,  and  other  processes.  With  solutions  of  these  sensitizing 
bodies  the  washed  plates  are  coated  and  left  to  dry.  By  coating  the 
plates  with  such  a  preservative  they  not  only  become  more  sensitive, 
but  also  more  permanent. 

The  necessary  washing  and  coating  of  dry  plates  with  a  preserva- 
tive make  the  labor  somewhat  complicated.  The  development  is  still 
more  troublesome ;  the  dry  plate  must  first  be  prepared  for  receiv- 
ing the  fluids  by  soaking  respectively  in  water  and  in  a  silver  solution. 
The  too  energetic  sulphate  of  iron  developer  is  apt  to  give  rise  to  fogs 
and  spots,  and  the  preference  is  given  to  the  slower  acting  pyrogallic 
acid,  or  a  solution  of  sulphate  of  iron  with  the  addition  of  organic 
substances,  which  have  the  peculiarity  of  retarding  the  chemical  re- 
ducing process, — for  instance,  gelatin. 

In  a  dry  process  two  points  are  of  importance.  (1.)  The  dura- 
bility. (2.)  The  sensitiveness  of  the  plates.  These  are  very  variable. 
Many  dry  processes,  for  instance,  the  morphia  process,  produce  sensi- 
tive plates,  which,  however,  do  not  keep  long.  For  long  journeys 
more  regard  for  keeping  than  sensitiveness  should  be  had.  By 
many  preparations  the  quality  of  the  cotton  has  a  greater  influence 
on  the  quality  of  the  plates  than  in  the  wet  process,  many  even  re- 
quiring cotton  prepared  at  a  high  temperature,  whose  side  ingredi- 
ents have  an  essential  influence.  We  advise  a  preliminary  albumen- 
izing  before  collodionizing  all  dry  plates,  or  at  least  edging  with 
caoutchouc,  or  the  film  may  come  off,  or  tear  very  readily  during  de- 
velopment. In  addition,  we  advise  before  developing,  to  flow  the 
plates  with  alcohol  80°,  then  wash ;  the  developer  will  penetrate  the 
film  better. 

It  is  not  my  purpose  here  to  give  a  description  of  all  dry  processes 
which  have  been  practiced.  So  I  shall  confine  myself  to  the  descrip- 
tion of  two  which  I  have  worked  successfully. 


England's  collodio- albumen  process.  209 


THE  ALBUMEN  DRY  PROCESS. 

The  oldest  dry  process  is  that  of  Taupenot ;  it  consists  in  the  em- 
ployment of  an  albumen  film,  which  is  silvered  afterwards.  The 
albuminate  of  silver  takes  here  the  part  of  the  sensitizer. 

1.  England's  collodio-albumen  process. 

This  process  is  a  variation  of  Taupenot's,  for  which  we  are  indebted 
to  the  celebrated  landscape  photographer,  Mr.  England,  and  has 
been  worked  with  the  greatest  success  by  Herr  Prumm.  It  is 
noted  for  the  durability  of  the  plates.  Priimm  says :  It  seems  the 
elements  of  durability  combined  in  itself,  because  the  preservative 
is  almost  wholly  removed  after  it  has  done  its  action  on  the  film. 
For  it  is  certain  that  a  preservative  film,  left  on  the  plate,  protecting 
it  of  course  for  a  time  from  external  influences,  thereby  keeping  the 
plate  clean,  in  a  damp  atmosphere  acts  injuriously  and  quickly  on  the 
plate. 

The  England  process  depends,  briefly  stated,  on  the  following  man- 
ipulation : 

I.  A  bromo-iodized  plate  is  sensitized  as  usual. 

I  a.  The  plate  is  then  washed  until  all  greasy  lines  have  disap- 
peared. 

II.  A  solution,  consisting  of  the  well-beaten  white  of  eggs,  to 
which  has  been  added  a  small  quantity  of  distilled  water,  and  2 
to  4  drops  of  liquid  ammonia  for  each  egg  used,  is  poured  on  the 
plate,  and  moved  to  and  fro  for  about  one-quarter  to  a  half 
minute. 

Ila.  The  albumenized  plate  is  placed  in  a  second  dish  of  distilled 
water,  and  worked  pretty  freely  to  and  fro  to  remove  all  the  super- 
fluous albumen.    Should  one  washing  not  suffice  it  must  be  repeated. 

III.  A  thirty-grain  solution  of  nitrate  of  silver,  with  a  few  drops 
of  acetic  acid  added,  serves  to  change  the  albumen  into  silver  albumi- 
nate, and  that  is  accomplished  by  pouring  it  on  the  plate  and  moving 
to  and  fro  for  about  half  a  minute. 

Should  any  albumen  remain  it  will  show  it  immediately  by  a 
milky  precipitate ;  the  next  plate  must  then  be  washed  more  care- 
fully, as  faults  might  occur  if  neglected. 

Ill  a.  The  plate  is  now  thoroughly  washed  under  a  stream  of  water, 
to  remove  all  soluble  bodies,  and  set  aside  to  dry. 

The  manipulations  can  be  performed  more  conveniently  and  quicker 
in  practice  than  would  appear  from  the  above  description.    If  you 

14 


210 


THE  PRACTICE  OF  PHOTOGRAPHY. 


have  an  assistant,  you  can  work  hand-in-hand,  so  that  no  moment  is 
lost,  and  in  one  hour  fifteen  plates  can  be  prepared,  the  size  of  which 
is  of  little  consequence. 

It  is  advisable  to  use  a  collodion  made  of  woolly  pyroxylin,  it 
not  being  required  in  this  process  to  use  short-fibred  cotton.  Priimm 
formerly  was  of  a  different  opinion,  and  had  used  for  his  attempts  a 
powdery  cotton  prepared  at  a  high  temperature.  This  showed  such 
a  considerable  structure  that  he,  in  adding  one  part  of  the  bromine  to 
two  or  three  parts  of  iodine  to  the  ordinary  used  portrait  collodion, 
obtained  perfect  and  good  results.  In  the  preparation  the  exclusion  of 
all  white  daylight  is  essential,  the  least  action  of  which  will  produce 
fogging,  therefore,  on  account  of  the  length  of  time  required  for  pre- 
paring, more  care  is  necessary  than  in  the  using  of  wet  plates. 

The  surplus  albumen  and  silver  flowing  off  the  plate  can  be  caught, 
and,  with  the  addition  of  fresh  solution,  used  again.  In  this  manner 
the  quantity  of  albumen  and  silver  used  is  so  small  that  it  would  not 
be  worth  mentioning. 

The  drying-closet  must  be  provided  with  good  ventilation ;  if  not, 
the  plates  will  dry  very  slowly.  The  application  of  chloride  of  cal- 
cium is  also  advisable,  to  remove  all  superfluous  dampness  out  of  the 
air,  but  will  not  suffice  by  itself.  Every  interruption  in  the  drying 
will  be  an  observable  defect. 

The  plate  is  in  this  respect  very  sensitive ;  if,  for  instance,  the  door 
of  the  drying-box  is  opened  before  the  plates  are  dry,  a  dark  line 
will  appear  afterwards  exactly  as  far  as  the  plate  was  damp  when  the 
interruption  took  place.  Even  the  circulation  of  air  of  a  different 
temperature  is  sufficient  to  produce  this  effect.  I  emphasize  this 
point,  that  the  plates  may  be  left  in  the  box  and  not  removed  too 
soon.  It  is  not  advisable  to  heat  the  box  before  the  removal.  A  tem- 
perature of  15 — 25°+K.  will  answer  the  purpose.  The  drying  will 
take  about  8  to  12  hours,  when  a  large  quantity  is  dried  at  once. 
Smaller  quantities  take  less  time. 

In  packing  the  plates,  a  plate-box  with  diagonal  rabbet  is  recom- 
mended as  of  some  importance  (see  Fig.  65) ;  in  the  ordinary  rabbet 
(see  first  figure),  the  edge  of  the  film  is  rubbed  off. 

In  regard  to  the  time  of  exposure,  with  dry  plates,  the  most  sin  is 
committed.  All  aim  at  short  exposures,  wherein  there  is  no  advan- 
tage, as  it  has  to  be  calculated  by  minutes.  Priimm  advised  on  the 
contrary  a  long  exposure ;  for  instance,  if  four  minutes'  exposure  is 
sufficient,  expose  six ;  an  underexposure  will  therefore  very  rarely 
occur.  On  the  other  hand,  the  developing  is  decidedly  easier.  Besides 
this  there  is  another  advantage  not  to  be  undervalued.    In  taking  a 


RESIN  DRY  PLATE  PROCESS  OF  HARNECKER.  211 

view  with  trees  during  a  wind  there  will  be,  if  the  wind  is  not  too 
strong,  at  times  a  lull,  which,  by  repeated  repetitions,  in  long  exposure, 
marks  itself  sharply,  while  in  a  short  exposure,  which  might  have 
occurred  during  the  movement,  everything  will  appear  in  a  confused 
mass.  Should  the  wind  come  in  puffs,  the  cap  can  be  placed  on  the 
tube  until  they  pass.  The  same  defects  resulting  from  underexposure 
are  obtained  by  too  much  haste  in  developing.  This  also  requires 
time  and  patience.  All  details  must  have  appeared,  the  green  of  the 
trees  must  show  all  the  gradations,  before  giving  energetic  intensifying 
a  thought.  Prumm  applied  to  the  above  the  acid  developer,  namely, 
at  first  a  very  slight  addition  of  citric  acid  to  the  pyrogallic  acid. 
The  effects  were  the  same  as  intensifying.  Ordinarily  the  first  part 
of  the  development  is  done  with  clear  pyrogallic  acid  solution,  which 
produced  a  fog  for  Prumm,  which  disappeared  on  the  slightest  addition 
of  citric  acid.  As  soon  as  the  first  details  appear  a  very  small  quan- 
tity of  silver  is  added.  It  is  of  course  understood  that  the  plate  has 
been  long  exposed.  In  the  opposite  case  no  preliminary  silver  should 
be  used  if  a  good  plate  is  desired. 

The  developing  is  a  thing  of  practice,  like  no  other  in  the  whole 
dry  process.  Do  not  fear  spoiling  a  few  plates ;  by  this  modifying 
the  development  you  will  yourself  find  the  best  mode  of  manipula- 
tion, for  each  plate  must  be  handled  differently,  and  this  is  what 
makes  this  process  interesting.  Prumm  also  recommends  developing 
in  a  small  flat  dish,  for  many  failures  are  avoided  in  this  manner 
without  much  loss  of  the  solutions  used.  In  regard  to  the  keeping 
qualities  of  the  plates  he  thinks  that  with  care  they  keep  a  very 
long  time.  Prumm  kept  his  for  6  weeks,  and  developed  them  4  or 
5  days  after  the  exposure. 

2.  THE  RESIN  DRY  PLATE  PROCESS  OF  HARNECKER. 

A  well-cleaned  glass  plate  is  coated  with  common  collodion,  to 
which  for  every  100  grammes  (3  oz.,  231  gr.)  y^th.  of  a  gramme  of 
resin  (H  gr.)  is  added.  When  the  last  drop,  after  pouring  off  the 
excess,  has  become  dry,  the  plate  is  dipped  in  a  good  working  silver 
bath : 

Silver,  15  parts. 

Water,        .       .       .       .    130  " 

Nitric  acid,  ....       2  drops  for  every  4  oz.  of  solution.* 


*  I  give  above  the  original  receipt,  but  believe  it  would  be  well  to  add  to 
the  silver  bath  one-quarter  per  cent,  of  the  dry  salt  of  iodide  of  potassium. 


212 


THE  PRACTICE  OF  PHOTOGRAPHY. 


The  most  suitable  temperature  is  65°  Fahrenheit ;  the  time  of 
sensitizing  5,  8,  and  10  minutes.  The  medium  time  is  generally  the 
best.  The  silver  plate  is  first  well  washed  with  filtered  distilled 
water,  and  next  thoroughly  washed  with  ordinary  water.  Finally  it 
is  rinsed  with  distilled  water,  and  placed  on  one  corner  to  dry,  at  a 
temperature  of  not  less  than  70°  Fahrenheit  nor  more  than  100°. 
When  dry  the  plates  are  ready  for  use. 

The  exposure  is,  according  to  the  intensity  of  the  light  or  the  age 
of  the  plate,  twice  or  three  times  that  of  a  wet  plate.  Fresh  plates 
are  much  more  sensitive  than  old  ones. 

The  plate  is,  previous  to  the  development,  placed  into  a  dish  con- 
taining filtered  distilled  water  (it  is  best  to  make  the  water  slightly 
acid).  The  dish  should  be  moved  to  and  fro,  and  the  plate  soaked 
in  it  for  from  five  to  ten  minutes.  It  is  then  taken  out  and  placed  in 
the  same  silver  bath  in  which  the  plate  has  been  originally  sensitized. 
It  is  raised  and  lowered  from  eight  to  nine  times,  and  developed  like 
any  other  wet  plate. 

The  developer  consists  of : 

Sulphate  of  iron,  1  part. 

Water,   220  parts. 

Glacial  acetic  acid,  3  " 

Alcohol,  4  to  5  parts. 

Intensified  with  the  following  solutions  : 

a.  Pyrogallic  acid,   5  parts. 

"Water,  .    2560  « 

b.  Nitrate  of  silver,   15  " 

Water,   720  « 

Glacial  acetic  acid,   32  " 

Fixed  with  a  solution  of  hyposulphite  of  soda.  The  development 
can  also  be  made  by  pouring  the  above  iron  solution  over  the  soaked 
plate.  It  is  moved  for  a  few  seconds  over  the  plate,  poured  back 
into  a  glass,  and.  then  are  added  two,  or  at  most  three,  drops  of  a 
silver  solution,  consisting  of : 

30  parts  of  silver  dissolved  in  720  parts  of  water,  and  mixed  with 
the  following  fluid  : 

30  parts  of  citric  acid  dissolved  in  720  parts  of  water. 
60      »  alcohol. 

The  picture  becomes  visible  at  once,  and  the  plate  can  be  washed 
after  the  fluid  has  been  poured  over  it  several  times,  and  the  image 
appears  clear  and  perfect.  After  washing  with  ordinary  water,  the 
picture  is  reintensified  with  pyrogallic  acid :  but  the  acid  must  be 


THE  BROMO-COLLODION  PROCESS. 


213 


used  without  the  addition  of  silver  in  order  to  avoid  fogging.  After 
the  pyrogallic  acid  has  been  poured  off  and  on  several  times,  citrate 
of  silver  is  added  for  intensifying.  If  care  has  been  taken  in  the 
preparation  of  the  plate,  not  to  have  the  collodion  too  dry  before  the 
plate  is  dipped  in  the  bath,  and  it  is  left  immersed  sufficiently  long, 
and  afterwards  well  washed,  a  satisfactory  result  is  certain,  particu- 
larly when  pictures  in  the  open  air  and  landscapes  are  taken. 
The  development  can  be  made  at  any  time  after  the  exposure. 


Russel's  tannin  process  is  one  of  the  oldest  and  easiest  working 
methods,  if  the  precautions  are  heeded  which  are  mentioned  above. 
Always  use  albumenized  plates  for  it.  The  following  is  the  collodion 
used : 


Bromide  of  cadmium,   ....    1  gramme. 
Iodide  of  cadmium,      .       .       .       .1  gramme. 
Dissolved  in 

Alcohol,  .  .  30  grammes,  filtered  and  thinned 
with  90  grammes  of  plain  col- 
lodion of  2  per  cent. 


The  plates  are  silvered  by  remaining  five  minutes  in  the  following 
bath: 

10  grammes  nitrate  of  silver. 
100  grammes  water. 
1-2  drops  nitric  acid. 

4  cubic  cent,  of  a  solution  of  iodide  of  potassium,  1  :  100. 

The  plate  is  rinsed  in  distilled  water,  then  washed  under  a  tap, 
again  washed  with  distilled  water,  then  flowed  with  the  following 
solution : 


In  regard  to  the  developing,  wash  the  plate,  flow  with  pyro  (the 
same  as  in  redeveloping)  ;  by  this  a  very  faint  image  appears.  Let 
the  pyro  run  into  a  glass,  add  a  few  drops  of  citrate  of  silver  solution, 
intensify,  and  fix  as  usual. 


The  bromo-collodion  process  was  discovered  by  Lea,  and  is  distin- 
guishable from  all  others,  as  no  iodide  of  silver  is  used,  no  acid,  but 
only  alkaline  developer ;  finally,  the  silver  bath  is  totally  put  aside 


3.  russel's  tannin  process. 


Tannin, 
Water, 


9  grammes,  dissolved  in 
30  grammes,  then  dried. 


4.  THE  BROMO-COLLODION  PROCESS. 


t 


214 


THE  PRACTICE  OF  PHOTOGRAPHY. 


by  the  use  of  a  silvered  collodion.  The  latter  is  not  absolutely 
necessary.  Bromized  collodion  containing  2  to  2J  per  cent,  bromide 
of  cadmium  can  be  silvered  in  a  bath  free  from  iodide  of  silver.  In  a 
bath  containing  iodide,  iodide  of  silver  is  precipitated  on  the  bro- 
mized plate,  and  then  manipulated  as  described  below.  Lately, 
in  England,  Wortley  improved  the  process.  He  prepares  bromo- 
collodion  dry  plates  for  the  trade  as  well  as  the  silver  collodion 
(called  bromo-silver  emulsion). 

The  bromide  process  is  very  simple  if  too  great  sensitiveness  is  not 
desired.  Should  this  be  the  case,  none  of  the  published  formulae 
will  answer  to  obtain  similarity  in  the  result.  As  above  stated,  a 
cotton  prepared  at  a  high  temperature  is  important.  The  alkaline 
development,  which  in  this  case  is  of  great  importance,  is  an  American 
discovery.  Lea  is  reported  to  have  been  the  first  one  to  publish  it. 
In  this  method,  instead  of  using  pyrogallic  acid  with  the  addition  of 
acid  and  silver,  it  is  used  with  the  addition  of  ammonia.  The  mix- 
ture of  pyrogallic  acid  and  ammonia  reduces  the  bromide  of  silver, 
acted  on  by  the  light,  thereby  causing  the  picture  to  appear.  The 
alkaline  developer  acts  very  feebly  on  iodide  of  silver,  therefore  it 
can,  in  this  case,  be  dispensed  with. 

A  certain  opacity  of  the  plates  is  of  importance  for  this  dry  process, 
which  is  attained  by  the  addition  of  ammonia  or  Rochelle  salts.  1  part 
is  dissolved  in  8  parts  of  alcohol,  and  30  drops  added  to  30  grammes 
of  bromo-collodion.  Wortley  adds,  besides  the  above,  2  grammes 
nitrate  of  uranium  to  30  grammes  of  collodion.  The  effect  of  it  is 
doubtful. 

Cooper  says  the  more  sensitive  the  plates  the  more  difficult  it  is  to 
avoid  spots  and  other  inconveniences,  and  for  purposes  where  it  does 
not  necessitate  a  short  exposure,  the  emulsion  plates,  with  a  slight 
excess  of  bromide,  are  the  cleanest  and  surest,  and  for  many  pur- 
poses, such  as  architectural  views,  to  be  preferred  to  the  more  sensi- 
tive plates.  Wortley,  on  the  contrary,  claims  that  an  excess  of 
nitrate  of  silver  is  necessary  in  the  emulsion  collodion.  A  solution 
of  caoutchouc  in  chloroform  is  used  as  a  preliminary  coating,  in  case  a 
strongly  gummed  preservative  is  used;  for  a  less  gummy  preservative 
the  albumen  is  the  best  and  cheapest.  Without  this  preliminary 
coating  the  plates  are  easily  injured,  even  destroyed  in  developing. 
The  gum  causes  blisters  as  soon  as  the  collodion  is  a  little  tough. 
Lea  has  varied  his  formula  many  times  and  improved  it.  He  gives 
lately  the  following  as  the  best. 

The  dry  processes  known  up  to  the  present  time  divide  themselves 
naturally  into  two  very  distinct  classes,  those  like  the  Taupenot, 


THE  BROMO -COLLODION  PROCESS. 


215 


Fothergill,  English,  and  other  processes,  in  which  the  chief  constitu- 
ent of  the  preservative  is  albumen,  and  on  the  other  hand  those  like 
the  gum  gallic,  the  tea,  pyrogallic  acid,  tannin,  and  other  processes 
in  which  no  albumen  is  used.  The  albumen  processes  have  certain 
well-marked  and  excellent  characteristics,  but  they  are  all  slow 
and  require  long  exposures.  Nevertheless  it  has  been  found  for  some 
years  past  in  England,  where  dry-plate  work  is  very  popular,  that  a 
large  proportion  of  the  best  prints  exhibited  were  made  from  negatives 
belonging  to  the  class  of  albumen  preservatives. 

On  my  return  to  America  last  summer  I  commenced  a  series  of 
experiments  to  ascertain  whether  the  advantages  of  these  two  differ- 
ent systems  could  not  be  combined,  and  whether  a  satisfactory  rapidity 
could  not  be  imparted  to  albumen  plates,  whilst  preserving  their 
delicacy  and  fine  modulation.  In  this  attempt  I  have  recently  suc- 
ceeded, even  beyond  my  hopes,  and  have  obtained  a  process  differing 
in  all  its  essential  features  from  any  now  in  use.  It  is  a  collodio-albu- 
men  dry  process,  and  yet  as  rapid  as  the  wet.  At  the  same  time,  in 
simplicity  and  quickness  of  manipulation,  I  believe  I  may  say  it  ex- 
ceeds all  other  dry  processes. 

Before  proceeding  to  the  details  I  may  be  permitted  a  few  words  of 
explanatory  preface. 

When  in  the  year  1866  I  first  took  up  the  study  of  the  emulsion 
process  several  formulas  had  been  published,  and  some  of  these  called 
for  the  presence  of  silver  nitrate  in  excess  of  what  is  needed  to  decom- 
pose the  soluble  bromides  in  the  collodion.  But  at  that  time,  the  sil- 
ver nitrate  was  always  added  in  powder,  and  much  of  it  did  not  pass 
into  solution.  There  was  a  tendency  for  the  grains  of  nitrate  instead 
of  dissolving  to  become  coated  with  silver  bromide,  and  then  to  resist 
the  weak  solvent  power  of  the  collodion.  I  introduced  the  system  of 
dissolving  the  silver  nitrate  by  heat  in  a  portion  of  alcohol,  and  add- 
ing this  to  the  bromized  collodion  and  at  once  agitating  violently.  In 
this  way  all  of  the  silver  salt  was  got  into  solution,  and  then  I  found 
that  whenever  the  silver  nitrate  was  present  in  excess,  the  plates  invar- 
iably fogged.  After  a  continued  research  I  found  that  this  could  be 
obviated  in  two  ways,  either  by  the  introduction  of  a  chloride  into  the 
bromide  collodion,  or  by  the  addition  of  aqua  regia.  The  latter  I 
gave  the  preference  to,  and  the  general  experience  of  photographers 
during  the  years  that  have  elapsed  since  then,  has  confirmed  that  opin- 
ion. Sometimes,  indeed,  an  advantage  is  gained  by  combining  both 
methods. 

The  behavior  of  the  emulsion  made  with  silver  nitrate  in  solution 
proved  absolutely  that  up  to  that  time  no  plate  had  ever  been  made 


216 


THE  PRACTICE  OF  PHOTOGRAPHY. 


with  silver  nitrate  in  excess.  The  excess  had  lain  at  the  bottom  in 
powder  and  inert.  Its  doing  so  was  all  that  saved  the  plates.  Had 
it  dissolved,  they  would  have  fogged.  The  addition  of  a  chloride  or 
of  aqua  regia  first  rendered  it  possible  to  use  silver  nitrate  in  excess, 
and  the  gain  in  sensitiveness  was  immense.  At  first  the  extent  of  the 
advantage  was  hardly  recognized,  but  latterly  it  has  been  thoroughly 
appreciated.  In  describing  the  action  of  aqua  regia,  I  stated  that  any 
amount  of  excess  of  silver  nitrate  might  be  employed,  but  that  I  found 
the  best  results  came  with  a  small  excess.  I  regret  to  say  that  shortly 
after  a  most  unexampled  attempt  was  made  to  appropriate  my  pro- 
cess on  the  strength  of  simply  varying  the  proportion  of  silver  nitrate. 
By  some  this  variation  was  held  to  be  an  improvement,  whilst  other 
photographers  found  that  they  succeeded  best  with  my  formulae. 
Whilst  these  discordant  results  -in  nowise  justified  the  attempted  ap- 
propriation the  fact  nevertheless  remained  unexplained,  why  such  dif- 
ferent conclusions  should  have  been  come  to  by  different  experimenters. 

It  was  not  until  some  time  after  that  I  succeeded  in  solving  this 
enigma.  I  found  that  different  preservatives  required  very  different 
proportions  of  silver  nitrate.  Up  to  that  time  it  had  been  customary 
to  recommend  one  and  the  same  proportion  of  silver,  no  matter  what 
preservative  was  to  follow.  This  system  was  essentially  wrong,  for 
each  different  preservative  has  its  definite  proportion  of  silver  salts 
with  which  it  gives  its  best  results.  The  less  sensitive  the  preservative, 
the  larger  the  quantity  of  silver  nitrate  which  it  requires. 

For  a  long  time  I  had  worked  with  the  cochineal  preservative 
which  I  had  proposed.  This  is  the  most  sensitive  of  all  preservatives 
known  up  to  this  time ;  it  therefore  requires  to  be  worked  with  a  very 
moderate  excess  of  silver  nitrate  ;  if  more  be  used,  the  plates  are  found 
to  solarize  easily,  and  if  at  all  overexposed,  are  found  to  intensify  with 
great  difficulty. 

Subsequently  I  tried  pyrogallic  acid  and  got  very  excellent  results. 
This  substance  proved  to  be  less  sensitive  than  cochineal,  but  I  found 
that  this  inferior  sensitiveness  could  be  compensated  for  by  increasing 
the  nitrate,  which  increase  was  borne  in  this  case,  though  it  would 
not  have  been  in  the  case  of  the  cochineal.  By  further  experiments 
I  succeeded  in  establishing  the  general  law  that  I  have  stated  above, 
viz.,  that  the  less  sensitive  the  preservative,  the  larger  the  proportion 
of  silver  needed  for  it.  So  that  we  have  a  regular  series,  cochineal, 
pyrogallic  acid,  gallic  acid,  and  tannin,  diminishing  in  sensitiveness 
from  the  first  to  the  last,  and  each  member  requiring  considerably 
more  silver  than  the  next  member  before  it. 

As  albumen  is  a  preservative  considerably  less  sensitive  than  any 


THE  BROMO-COLLODION  PROCESS. 


217 


four  just  mentioned,  less  sensitive  even  than  tannin,  it  is  clear  that  if 
it  be  used  in  the  preservative  bath,  the  dose  of  silver  must  be  very 
large  in  order  that  we  may  obtain  a  high  degree  of  sensitiveness,  and 
it  also  follows  that  this  large  dose  will  be  borne  without  those  incon- 
veniences that  accompany  its  use  with  the  more  sensitive  preservatives. 
This  is  to  be  expected,  even  if  the  albumen  be  mixed  with  more  sensi- 
tive preservative  agents,  for  as  I  have  already  shown  elsewhere,  when 
two  preservative  agents  of  different  degrees  of  sensitiveness  are  mixed, 
the  result  will  be  a  degree  of  sensitiveness  intermediate  between  the 
two,  but  rather  inclining  to  be  less  sensitive. 

Applying  this  principle  I  succeeded  at  once  in  obtaining  very  sen- 
sitive albumen  plates,  indeed,  far  more  sensitive  than  any  one  would 
have  believed  that  albumen  plates  could  be.  It  is  needless  here  to 
give  the  formula,  since  it  has  been  superseded  by  a  further  improve- 
ment which  I  have  just  made,  and  shall  now  describe,  and  which  is  a 
complete  departure  from  all  existing  methods  both  in  principle  and 
in  practice. 

The  albumen  plates  which  I  first  made  were  prepared  in  the  method 
usual  with  emulsion  plates.  The  glasses  were  edged  and  then  coated 
with  emulsion,  plunged  into  water,  and  washed  till  the  greasy  lines 
disappeared,  then  passed  into  the  albumen  preservative  and  dried. 

In  reflecting  over  this  process,  it  occurred  to  me  that  silver  nitrate 
was  so  completely  precipitated  by  albumen,  that  there  could  be  no 
reason  or  advantage  in  this  preliminary  washing.  That,  on  the  con- 
trary, it  was  probable  that  a  better  result  would  be  got  by  plunging 
the  plate  directly  into  the  albumen  bath  as  soon  as  set. 

The  importance  of  this  change  seemed  so  great  that  I  first  experi- 
mented with  it  in  the  following  manner.  An  emulsion  was  taken 
with  a  very  large  excess  of  silver  nitrate,  an  excess  of  ten  or  twelve 
grains  to  the  ounce.  This  large  excess  was  to  make  the  trial  more 
decisive,  and  for  the  same  reason,  the  plate  was  coated  twice,  so  as  to 
get  a  very  thick  film  with  a  large  quantity  of  silver  nitrate.  A  solu- 
tion of  albumen  was  prepared,  which,  to  increase  the  severity  of  the 
trial,  was  made  very  dilute,  one  per  cent,  only  of  albumen  dissolved 
in  water,  half  a  drachm  of  albumen  to  six  ounces  water.  Into  this 
the  plate  was  plunged  as  soon  as  set.  It  was  taken  out  when  the 
greasy  lines  had  disappeared  and  the  bath  was  tested  for  silver  nitrate. 
None  had  been  removed  from  the  plate,  and  this  was  also  the  case  (or 
only  the  very  faintest  infinitesimal  trace)  when  the  plate  had  been  left 
in  some  time  longer.  All  the  silver  had  been  converted  into  silver 
albuminate  within  the  film,  so  that  evidently  the  previous  washing  as 
always  hitherto  practiced  could  be  dispensed  with  advantageously, 


218 


THE  PRACTICE  OF  PHOTOGRAPHY. 


at  least  with  an  albumen  preservative,  because  in  this  way  adarger 
quantity  of  organic  insoluble  silver  salt  was  retained  inside  the  film. 
The  above  trial  was  made  by  daylight. 

Experiment  with  plates  prepared  in  the  dark  and  exposed  in  the 
camera  gave  the  fullest  confirmation  of  the  expectations  I  had  formed  : 
in  fact  the  gain  was  much  greater  than  I  had  ventured  to  hope. 

So  that  now  I  conclude  that  when  albumen  is  used,  the  washing  of 
the  plate  is  just  as  injurious  and  unnecessary  as  would  be  the  washing  of 
an  ordinary  wet  plate  before  plunging  it  into  the  silver  bath.  The  wet 
and  dry  processes  are  thus  brought  curiously  together,  for  in  both  the 
plate  is  collodionized,  and  then  simply  plunged  into  a  bath,  and  is 
then  finished.  The  albumen  plate  may  be  either  dried  or  used  wet ; 
when  wet  it  is  even  more  sensitive  than  when  dry. 

The  simplification  obtained  in  this  way  is  sufficiently  evident,  and 
the  diminished  trouble  in  making  the  plates,  also  the  difficulty  about 
pure  water  for  the  washing.  But  these  considerations  are  very  unim- 
portant compared  with  the  gain  to  the  plate  itself.  The  advantages 
are : 

1.  It  is  much  more  sensitive.  With  an  equal  exposure  the  develop- 
ment is  over  in  one-fourth  the  time,  and  with  one-fourth  as  much  am- 
monia carbonate. 

2.  The  irradiation  and  blurring  are  greatly  diminished.  Small 
dark  objects  projected  against  a  bright  sky  are  depicted  clean  and 
sharp.  Small  leafless  twigs  in  deep  shadows  standing  against  a  bright 
sky,  instead  of  having  an  indistinct  and  blurred  effect,  come  out  as 
sharp  as  if  they  had  been  cut  in  the  film  with  an  engraving  tool. 

3.  There  is  better  detail  in  the  deep  shadows,  and  more  variety  of 
half  tone. 

4.  Much  less  tendency  to  spots  and  pinholes. 

I  shall  now  proceed  to  give  the  formula?.  Besides  the  introduction 
of  albumen  to  the  emulsion  process,  and  the  change  respecting  the 
washing,  I  have  found  several  other  improvements  which  promise  to 
be  valuable.  I  find  an  advantage  in  adding  cobalt  chloride  to  the  col- 
lodion, and  an  alkaline  nitrite.  These  two  changes  are  of  less  impor- 
tance than  those  previously  mentioned.  They  are  not  essential  and 
may  be  omitted,  but  they  have  their  utility,  and  I  prefer  to  employ 
them.  Another  change  of  more  importance  is  the  following.  In  pro- 
cesses in  which  albumen  has  been  used,  it  has  hitherto  taken  the  place 
of  other  preservatives.  I  use  it  in  connection  with  them,  that  is,  with 
gallic  acid,  pyrogallic  acid,  gum,  etc. 


THE  BROMO-COLLODION  PROCESS. 


219 


Collodion. 


Dry  cadmium  bromide, 
Ammonium  bromide,  . 
Pyroxylin,  . 
Ether,  . 
Alcohol, 


48  » 
240  " 


200  grains. 


20  fluid  ounces. 
12  » 


To  this  may  be  added  with  advantage : 


Cobalt  chloride, 
Potash  nitrite, 


32  grains. 
32  « 


Potash  nitrite  dissolves  with  some  difficulty  in  alcohol.  Half  the 
twelve  ounces  of  alcohol  should  be  appropriated  to  dissolve  the  nitrite, 
the  other  salts  to  be  dissolved  in  the  other  half.  Keep  the  collodion 
in  a  warm  light  place  for  a  month.  Without  the  right  sort  of  cotton 
a  total  failure  will  result,  or  at  least  only  a  partial  success.  The  best 
pyroxylin  I  have  had  was  made  for  me. 

When  it  is  intended  to  prepare  an  emulsion,  three  or  four  ounces  of 
collodion  is  taken,  and  to  each  ounce  two  drops  of  aqua  regia  are 
added.  (Aqua  regia  is  easily  prepared  by  adding  half  an  ounce  of 
nitric  acid  to  an  ounce  of  hydrochloric  in  a  stoppered  vial,  and  setting 
in  hot  water  until  the  mixture  turns  orange  color.) 

The  silver  nitrate  in  fine  powder  is  weighed  out,  taking  twenty- 
three  grains  to  each  ounce  of  collodion  (if  the  cobalt  chloride  and 
potash  nitrite  are  used,  then  twenty-five  grains  silver  nitrate).  This 
is  dissolved  in  alcohol.  To  do  this,  take  a  large  test-tube,  capable  of 
holding  about  three  ounces,  so  that  the  alcohol  may  occupy  but  a 
small  space  at  the  bottom,  and  be  in  no  danger  of  boiling  over.  Cover 
the  powdered  nitrate  with  alcohol  about  an  inch  deep.  Boil  over  a 
gas  flame,  shake,  boil  again,  and  after  a  couple  of  minutes  pour  this 
into  the  bottle  of  collodion,  and  instantly  shake  well  for  a  couple  of 
minutes.  Pour  a  rather  less  quantity  of  alcohol  over  the  residue  in 
the  test-tube,  and  repeat.  The  third  time  ought  to  finish  the  solution, 
but  if  not  a  fourth  may  follow.  The  shaking  is  much  more  effective 
if  a  bottle  of  such  size  be  selected  that  it  is  only  about  one-third  filled. 
Of  course  it  must  be  wrapped  in  opaque  yellow  paper. 

After  about  ten  or  twelve  hours  it  will  be  ready  for  use.  In  the 
middle  of  this  interval  it  should  have  one  more  good  shaking.  Just 
before  using  it  should  be  filtered  through  sponge,  or  fine  close  linen. 

The  plates  should  be  edged  with  india-rubber  dissolved  in  benzole, 
the  edging  along  the  sides  not  quite  meeting  that  at  the  ends,  but 
leaving  an  opening  for  the  escape  of  water  under  the  film.  To  get  an 
even  coat,  pour  on  plenty,  carry  it  over  the  plate  quickly,  and  in  rocking, 


220 


THE  PRACTICE  OF  PHOTOGRAPHY. 


raise  the  far  end  but  little,  and  slowly.  These  three  rules  will  be  found 
very  useful. 

As  soon  as  set,  plunge  directly  into  the  preservative  bath. 

Preservative  Bath. 

Water,       .       .       .    •   8  ounces. 

Gum  and  sugar  solution,    .....  10  drachms. 

Prepared  albumen,   5  " 

60-grain  solution  of  gallic  acid  in  alcohol,  3  " 

60-grain  solution  of  tannin  in  water,  3  " 

The  tannin  may  be  used  or  left  out.  The  ingredients  must  be  added 
in  the  above  order,  or  a  flocky  precipitate  may  be  produced  which 
ruins  the  bath,  even  if  filtered  out. 

Gum-Sugar  Solution. — Dissolve  half  a  pound  of  good  gum  arabic 
and  three  ounces  of  white  lump  sugar  in  forty-four  ounces  water. 
Add  one  and  one-half  fluid  drachm  carbolic  acid  to  make  it  keep. 
Shake  well,  and  filter. 

Prepared  Albumen. — To  the  whites  of  five  eggs,  add  an  equal  bulk 
of  water,  and  a  quarter  ounce  of  acetic  acid  No.  8.  Shake  well,  and 
filter  through  sponge. 

Baching. — It  is  best  to  back  the  plates.  Take  one-quarter  pound 
annatto,  three  ounces  water,  one-quarter  ounce  glycerin,  one-half 
drachm  carbolic  acid.  It  will  take  about  two  days  for  the  annatto  to 
soften  in  the  water,  and  mix  up  to  a  thick  paste  to  be  applied  with  a 
brush.  If  the  paste  by  standing  dries  too  thick  for  use,  add  water, 
but  no  more  glycerin. 

Development. — For  a  whole-size  plate,  take  a  7  x  9  pan,  put  in  four 
ounces  of  water  and  half  a  drachm  of  sixty-grain  alcoholic  solution  of 
pyrogallic  acid.  Put  the  plate  in  (having  previously  removed  the 
backing  by  sponging),  leave  it  for  a  minute,  then  take  it  out,  and  put 
into  the  pan  one-half  drachm  of  fifteen-grain  solution  of  potassium 
bromide  and  half  a  drachm  of  eighty-grain  solution  of  flinty  (not 
powdery)  ammonium  carbonate.  If  the  exposure  has  been  suffi- 
cient, this  will  presently  bring  up  to  printing  density.  If  not,  add  a 
little  more  carbonate.  If  any  trouble  is  experienced  in  getting  den- 
sity, it  is  better  to  redevelop  with  citric  acid  and  silver,  either  before 
or  after  fixing.  If  the  image  is  very  faint,  redevelop  as  before.  But 
a  weak  image  indicates  bad  materials  or  some  mismanagement. 

Fixing. — Very  weak  hyposulphite,  one  ounce  to  the  gallon. 

The  negatives  obtained  by  this  process  are  not  only  excellent  in 
quality,  but  very  attractive  in  appearance,  much  more  so  than  ordi- 


POSITIVES  PRODUCED  IN  THE  CAMERA. 


221 


nary  dry-plate  negatives.  In  actual  practice  the  process  is  very  easy 
and  pleasant  to  work. 

As  regards  the  numerous  other  dry  processes,  such  as  the  tannin, 
gelatin,  coffee,  tea,  which  are  always  tried  over  and  over  again,  and 
always  recommended,  I  must  refer  the  reader  to  the  photographic 
periodicals,  whose  province  it  is  to  report  the  progress  made  in  this 
direction. 

To  any  one  who  desires  to  work  any  of  these  processes,  I  must 
recommend  once  more  the  greatest  care  and  cleanliness  in  the  treat- 
ment of  the  preparations.  A  slight  impurity,  which  in  the  wet  pro- 
cess would  perhaps  be  passed  by  unnoticed,  may  cause  a  perfect  fail- 
ure in  the  dry  process.  Many  dry  plate  pictures  owe  their  ill-success 
solely  to  the  employment  of  distilled  water  which  was  not  perfectly 
pure.  But  apart  from  this,  the  tedious  mode  of  preparing  dry  plates 
will  frighten  a  great  many.  Time  is  money ;  and  very  often  the 
packing  and  unpacking  for  an  excursion  of  the  necessary  apparatus 
and  chemicals  of  the  wet  process  offers  much  less  difficulty  and  loss 
of  time  than  the  preparation  of  a  number  of  dry  plates.  The  dry 
plate  process  will  only  then  become  practically  useful,  when  such 
plates  can  be  prepared  at  not  too  high  a  price  for  the  trade,  so  as  to 
save  the  photographer  the  trouble  of  making  them  himself. 

SECTION  II. 

PRODUCTION  OF  TRANSPARENT    POSITIVES  AND    REPRODUCTION  OF 

NEGATIVES. 

Transparent  positives  on  glass,  also  called  diapositives,  are  made 
with  the  aid  of  the  negative  process  in  the  camera,  or  by  direct 
printing  on  prepared  glass,  the  latter  being  only  practicable  when  the 
negative  is  perfectly  flat.  They  are  used  for  window-pictures,  magic- 
lantern  slides,  or  stereoscopic  pictures,  or  for  the  production  of  en- 
larged negatives. 

1.  TRANSPARENT  POSITIVES  PRODUCED  IN  THE  CAMERA. 

Two  cameras  are  used  for  this  purpose ;  the  fronts  are  placed  to 
face  each  other,  and  from  one  of  the  cameras  the  lens  is  removed. 
The  objective  of  the  second  camera  will  project  into  the  first  camera ; 
the  latter  serves  merely  as  a  proper  receptacle  for  placing  the  nega- 
tive and  to  exclude  side-light.  The  negative,  which  has  already  re- 
ceived the  necessary  retouch,  is  placed  in  the  plate-holder  of  the  first 
camera,  and  kept  in  position  by  small  pieces  of  wax,  and  the  plate- 


222 


THE  PRACTICE  OF  PHOTOGRAPHY. 


holder  is  placed  in  the  camera.  The  whole  system  is  best  placed  on 
a  long  and  very  solid  stand,  opposite  to  a  window,  with  an  unobstructed 
view  of  the  sky. 

I  generally  make  such  work  in  the  glass-house.  The  base  of  the 
stand  is  placed  in  an  inclined  position,  and  the  light,  with  the  excep- 
tion of  a  space  ten  feet  square,  is  excluded.  I  place  the  stand  with 
the  cameras  opposite  this  opening. 

It  is  advisable  to  exclude  all  superfluous  light.  When  the  back 
of  the  negative  receives  light,  it  will  look  partially  positive,  owing  to 
reflection.  This  of  course  may  give  rise  to  a  false  effect,  and  it  is 
better  to  cover  a  black  cloth  over  the  space  where  the  two  cameras 
are  joined  together.  And  the  light  which  passes  through  the  trans- 
parent margins  of  the  negative  also  exercises  an  injurious  influence. 
The  negative  acts  like  a  kind  of  window  admitting  diffused  light 
into  the  camera,  and  disturbs  the  clearness  of  those  parts  which 
should  remain  transparent  in  the  picture  which  we  desire  to  produce. 

To  obviate  this,  an  opaque  mask  is  placed  in  front  of  the  negative, 
in  which  an  opening  has  been  made  sufficiently  large  to  illuminate 
the  picture.  Window  bars  and  other  dark  objects  in  the  visual  line 
of  the  apparatus  are  disturbing  elements ;  to  make  them  harmless,  a 
piece  of  fine  ground-glass  is  placed  in  front  of  the  negative,  in  order 
that  the  light  must  first  pass  through  the  former  before  reaching  the 
negative.  The  back  shutter  of  the  plate-holder,  in  which  the  nega- 
tive rests,  is  prevented  from  shutting  by  some  simple  contrivance. 

A  correct  drawing  lens  of  short  focus  is  selected  as  an  objective. 
Carte  de  visite  lenses  of  four  inches  focus,  triplets,  or  aplanatic  lenses, 
answer  for  this  purpose.  The  bellows  of  the  back  camera  must  of 
course  admit  of  sufficient  extension  when  a  large  picture  is  desired. 

Card  and  triplet  objectives  should  be  fastened  in  a  reversed  position 
to  the  camera  (the  back  lens  being  front).  If  we  desire,  for  instance, 
a  picture  nine  times  magnified,  we  place  the  apparatus  in  such  a 
manner  that  we  receive  a  positive  which  has  been  magnified  three 
times ;  by  repeating  the  operation  without  changing  the  position  of 
the  apparatus,  and  substituting  the  magnified  positive  in  place  of  the 
original  negative,  we  will  get  a  picture  which  is  3  X  3,  or  nine  times 
as  large  as  the  original  negative.  It  is  only  necessary  to  focus  once, 
after  which  the  proper  stops  can  be  inserted.  The  exposure  should 
not  be  too  long.  The  developed  positive  should  show  by  transmitted 
light  the  same  delicate  details  in  ligh  t  and  half  tone  as  a  fine  paper  print 
taken  from  the  same  negative  would  represent.  A  fully  exposed  positive, 
soft  and  very  sharp,  is  absolutely  necessary  for  enlargements. 

Very  important  is  keeping  clear  of  the  lights  in  the  positives,  especi- 


POSITIVES   PRODUCED  IN  THE  CAMERA. 


223 


ally  those  intended  for  magic-lantern  slides.  The  ordinary  negatives 
have  nearly  always  a  very  fine  deposit  in  the  transparent  parts.  To 
prevent  this,  the  author  adds  5  drops  of  nitric  acid  of  1.  2  sp.  gr.  to 
100  cubic  centimetres  of  his  collodion.  Such  collodion  will  keep  only 
24  hours.  It  is  not  necessary  to  mix  any  more  than  is  required.  The 
developing  is  done  with  iron,  diluted  one-half  with  water. 

The  beginner  must  not  think  that  he  has  succeeded  when  a  clean 
positive  plate  has  been  produced.  Before  proceeding  further,  he 
should  examine  it  very  carefully  in  order  to  ascertain  if  it  is  rich  in 
detail.  Sir  H.  Davy  says,  expose  the  positive  until  it  shows  a  slight 
precipitate  in  the  bright  parts.  Intensifying  is  unnecessary.  When 
a  good  positive  has  been  obtained,  an  enlarged  negative  can  be  made 
from  it  in  the  same  apparatus.  Another  way  is  to  make  a  positive 
on  collodio-chloride  of  silver  by  the  direct  process,  which  will  be 
described  afterwards.  But  aside  from  focussing,  which  with  enlarge- 
ments requires  some  patience,  the  work  with  the  camera  is  the  most 
convenient. 

It  is  of  much  advantage  to  know  the  equivalent  focus  of  the  objec- 
tive for  the  purpose  of  focussing  (see  directions).  If  this  is  known 
the  negative  and  ground-glass  can  be  placed  at  about  the  distance  of 
the  equivalent  focus,  which  will  save  a  tedious  adjustment.  For 
pictures  of  original  size  the  distance  of  the  original  (negative)  as  well 
as  the  collodion  plate,  for  instance,  is  about  equal  to  twice  the  length 
of  the  focus.  For  enlargements  the  distance  of  the  original  is  less 
than  twice  the  focus.  Meagher,  in  London,  has  constructed  a  camera 
with  long  bellows,  which,  in  the  centre  of  the  bellows,  has  an  arrange- 
ment for  placing  the  objective,  and  in  the  front  part  of  which  the 
negative  is  easily  inserted.  All  the  parts  are  easily  brought  nearer 
or  further  removed  by  endless  screws,  and  sharp  focussing  causes  no 
trouble.  Any  one  who  has  to  work  much  in  this  branch  will  do  well 
to  make  marks  on  his  camera,  which  indicate  how  far  the  same  has 
to  be  drawn  out  for  different  enlargements. 

The  avoidance  of  any  shaking  of  the  apparatus  during  exposure  is 
absolutely  necessary.  Any,  even  the  slightest  motion  shows  in  the 
enlargement  in  a  heightened  measure,  and  produces  a  want  of  sharp- 
ness. Care  should  be  taken  to  have  a  solid  basis,  and  running  about, 
and  opening  and  shutting  doors,  etc.,  must  be  avoided.  Sometimes  a 
vibration  is  caused  by  the  opening  of  the  objective.  I  am  in  the  habit 
of  altogether  dispensing  with  a  cap,  and  admit  or  exclude  the  light 
with  a  small  piece  of  blackened  pasteboard,  which  is  placed  in  front 
of  the  negative,  and  can  easily  be  taken  away  for  the  purpose  of  ex- 
posure.   I  have  still  to  remark  that  it  is  advisable  to  subject  the  trans- 


224 


THE  PRACTICE  OF  PHOTOGRAPHY. 


parent  positive,  which  has  been  obtained  in  the  first  operation,  to  caref  ul 
retouching  before  we  take  a  new  negative  from  it.  If  rightly  exposed 
(which  must  be  found  by  trial),  a  very  flue  detailed  transparency  can 
be  produced  from  a  very  intense  negative.  If  the  positives  are  to  be 
used  for  window  pictures  they  are  toned  (after  fixing  and  washing) 
with  a  solution,  1  part  of  chloride  of  gold,  1000  parts  of  water.  Selle's 
uranium  intensifier  also  gives  a  pretty  color  (1  gramme  nitrate  of 
uranium,  1  gramme  red  prussiate  of  potash,  200  grammes  water). 

2.  TRANSPARENT    POSITIVES    PRODUCED  IN   THE  PRINTING-FRAME. 

The  albumen  process  is  the  best  adapted  for  this.  We  append  for 
this  the  excellent  formula  of  Edwards,  which  has  been  sold  in  England 
and  America  as  a  secrect.    The  following  solutions  are  required : 

1.  A  good  old  red  collodion. 

2.  Albumen :  The  white  of  10  eggs,  1\  grammes  water,  30  drops 
glacial  acetic  acid  ;  stir  thoroughly  with  a  glass  rod,  leave  stand  for  a 
few  hours,  strain  through  coarse  muslin,  then  filter  through  cotton  or 
a  sponge,  add  40  drops  ammonia,  and  3f  grammes  iodide  of  ammo- 
nium, 0.625  grammes  bromide  of  ammonium  dissolved  in  20  grammes 
of  water.  This  solution  it  is  said  will  keep  one  month  if  tightly 
corked,  in  a  cool  place. 

3.  Silver  bath :  30  grammes  nitrate  of  silver,  90  grammes  glacial 
acetic  acid,  240  grammes  water.  Iodize  the  bath  before  adding  the 
acid  ;  after  adding  the  silver  put  a  small  piece  of  camphor  in  the  bath. 

4.  Developer:  3|  grammes  pyrogallic  acid,  600  grammes  water, 
2  grammes  citric  acid. 

5.  Silver  solution :  2  parts  nitrate  of  silver,  100  parts  of  water. 
Manipulate  as  follows :    An  even  plate  is  coated  with  No.  1, 

washed  right  well,  then  flowed  with  No.  2,  run  off,  flow  again,  repeat 
for  each  corner,  dry  by  standing  on  several  thicknesses  of  filtering- 
paper,  or  placing  in  a  horizontal  position.  The  plate  must  not  be 
moved  while  drying.  The  dry  plate  is  dipped  in  the  silver  bath 
and  continually  moved  for  forty  seconds  (not  longer),  then  taken  out, 
washed,  flowed  with  distilled  water,  then  dried.  The  back  is  covered 
with  terra  sienna;  rub  up  with  gum  to  prevent  reflection.  The  expo- 
sure is  done  in  the  printing-frame,  requiring  in  clear  weather  3  to  15 
seconds,  according  to  the  density  of  the  negative,  which  must  be 
learned  by  experience.  After  exposure,  rinse  the  plate,  heat  the 
solution  No.  4  to  about  50  per  cent.  K.,  flow  over  the  plate,  let  run 
back  into  the  glass,  add  a  few  drops  of  No.  5,  flow  again,  moving  the 
plate  to  and  fro.  As  soon  as  all  the  details  are  visible,  wash  off  by 
rubbing  with  a  small  pad  of  cotton,  continue  the  developing  with 


POSITIVES  PRODUCED  IN  THE  PRINTING-FRAME.  225 

Nos.  4  and  5  until  sufficient  density  has  been  obtained.  Fix  in  the  fol- 
lowing solution : 

Hyposulphite  of  soda,  180  grammes ;  water,  600  grammes ;  chlo- 
ride of  gold,  \  gramme  (dissolved  previously  in  60  grammes  of  water). 
Leave  the  plate  in  here  about  fifteen  to  twenty  minutes ;  it  will  first 
get  brown,  afterwards  black  ;  wash  and  dry.  Varnishing  is  not  neces- 
sary. 

Besides  this  process,  the  collodio-chloride  of  silver  invented  by 
Simpson  is  used.  This,  however,  is  more  suitable  to  positives  on  white 
or  milk-glass  (so-called  American  porcelain  pictures),  which  produces 
a  wonderful  effect.  For  transparent  positives,  the  chloride  of  silver 
positive  does  not  appear  strong  enough.  These  pictures  are  not  de- 
veloped, but  gain  their  intensity  by  depth  in  printing  alone. 

The  white  of  four  eggs  is  beaten  to  a  froth  with  four  ounces  of 
water,  left  to  clear,  filtered  through  a  cloth,  and  spread  on  well-washed 
glass  plates.  The  coating  is  made  more  even  by  the  aid  of  a  glass 
rod,  and  the  plates  are  left  to  dry  in  a  place  free  from  dust.  They 
will  keep  for  months.  In  order  to  prepare  them,  they  are  first  coated 
with  Collodion  No.  1,  and  after  they  are  dry,  with  Collodion  No.  2 
(see  chapter  on  Porcelain  Printing)  ;  they  are  dried  again  and  printed 
in  a  printing-frame  under  a  negative,  which  is  backed  by  black  cloth. 
It  is  easy  to  control  the  printing,  as  the  picture  becomes  visible  through 
the  glass.  The  prints  must  be  vigorous.  The  plates  are  washed,  toned, 
and  fixed  in  the  same  manner  as  collodion  paper  (see  above),  and 
thus  a  fine  transparency  will  be  obtained  which  resists  mechanical 
injury  without  varnish.* 

If  this  operation  is  repeated,  a  new  negative  can  easily  be  made 
from  the  positive.  For  this  purpose,  however,  a  very  intense  print 
is  required,  and  the  best  way  will  be  not  to  tone  at  all  a  positive  pre- 
pared with  this  intention,  but  to  fix  it  at  once,  by  which  it  obtains  a 
brown  and  non-actinic  color. 

If  an  enlarged  print  is  desired,  the  positive  is  to  be  treated  as  stated 
below. 

Monckhoven  published  a  short  time  ago  some  extremely  important 
remarks  about  the  reproduction  of  negatives  by  means  of  collodio- 
chloride  of  silver.    He  says  : 

"  I  have  latterly  paid  a  great  deal  of  attention  to  the  chloride  of 
silver  process,  and  will  now  give  some  of  my  discoveries,  which  will 
enable  the  photographer  to  successfully  produce  new  negatives. 

"  I  formerly  believed  that  plates  prepared  with  collodio-chloride  of 


This  process  can  of  course  only  be  used  with  flat  negatives. 
15 


226 


THE  PRACTICE  OF  PHOTOGRAPHY. 


silver  ought  to  be  overexposed  in  order  to  obtain  vigorous  results. 
But  I  soon  found  out  my  error,  and  at  the  same  time  I  made  a  dis- 
covery the  practical  importance  of  which  will  be  evident  to  every  one. 

"  The  same  unforeseen  phenomenon  of  solarization  appears  with  the 
chloride  of  silver  plates  as  with  the  iodide  of  silver  plates,  and  in  such 
a  manner  that  if  a  plate  of  this  kind  has  been  exposed  too  long  to  the 
action  of  light,  all  the  shady  parts  acquire  by  reflection  the  well- 
known  metallic  lustre,  while  by  looking  through  them  the  red  tint 
will  be  noticed,  in  which  all  the  details  will  gradually  disappear. 
This  is  the  beginning  of  solarization  or  overexposure. 

"  The  light  acts  on  chloride  of  silver  (with  excess  of  nitrate  of  silver) 
in  exactly  the  same  manner  as  it  does  under  the  same  conditions  on 
iodide  of  silver,  i.  e.,  up  to  a  certain  point.  When  that  point  has  been 
reached  a  retrograde  action  sets  in. 

"  I  have  now  tried  to  avoid  the  solarization  of  the  chloride  of  silver 
plates,  or  at  least  to  defer  it,  and  I  succeeded  in  this  by  exposing  them 
to  the  vapors  of  ammonia. 

"  If  a  chloride  of  silver  plate  is  cut  in  halves,  the  one  exposed  to 
vapors  of  ammonia,  and  both  printed  under  a  negative,  the  difference 
is  very  perceptible;  the  one  will  be  solarized  very  soon,  while  the 
other  will  give  a  vigorous  picture  without  the  appearance  of  solariza- 
tion. 

"After  these  theoretical  explanations,  I  will  now  state  my  mode  of 


working. 

"  I  prepare  separately  the  following  solutions : 

a.  Normal  collodion — 

Gun-cotton,  1  part. 

Ether,   32  parts. 

Alcohol,   32  " 

I  let  it  settle  thoroughly,  and  only  use  the  portion  that  is  entirely 
clear. 

b.  Chloride  of  magnesium,        ....      1  part. 
Alcohol,  8  parts. 

After  the  chloride  has  dissolved,  the  solution  must  be  filtered. 

c.  Nitrate  of  silver  in  powder,  .       .       .       .20  parts. 

Distilled  water,  30  " 

Alcohol,  56  » 

The  silver  is  first  dissolved  in  water,  the  alcohol  then  added,  and 
finally  filtered. 

d.  Citric  acid  in  powder,  18  parts. 

Boiling  water,  18  " 

Alcohol,  128.6  " 


POSITIVES  PRODUCED  IN  THE  PRINTING-FRAME.  227 


The  citric  acid  is  first  dissolved  in  boiling  water  and  the  solution 
filtered  after  the  alcohol  has  been  added. 

"  For  compounding  the  collodion  a  brown  Rhine  wine  bottle  is 
taken,  for  in  such  it  will  keep  white  in  open  light.  It  is  filled  with 
600  parts  by  measure  of  normal  collodion  (a),  and  50  parts  by 
measure  of  chloride  of  magnesium  solution  (6).  This  is  well  shaken, 
and  60  parts  by  measure  of  silver  solution  (c)  added ;  the  bottle  is 
closed  and  shaken  for  a  few  minutes.  40  parts  by  measure  of  the 
citric  acid  solution  (d)  is  now  poured  in  ;  it  is  shaken  again,  and  the 
collodion  put  away  for  eight  or  ten  days,  for  it  improves  with  age. 

"  I  must  call  the  attention  of  the  reader  to  the  fact  that  he  must 
strictly  observe  the  above-mentioned  formulae,  for  the  preparation  of 
collodio-chloride  of  silver  must  be  carried  on  with  exactness.  If  too 
little  silver  is  present,  the  collodion  is  insensitive  to  light ;  too  much 
silver  produces  crystals  on  the  surface  of  the  plate.  In  the  former 
case  silver  salt  is  added ;  in  the  latter  chloride  of  magnesium. 

"  This  collodion  has  an  opalescent  color.  It  will  not  form  a  precip- 
itate if  it  has  been  correctly  prepared. 

"  The  plates,  after  being  carefully  cleaned,  are  coated  with  albu- 
men which  has  been  diluted  with  its  own  volume  of  water ;  they  are 
then  well  dried  and  collodionized.  The  collodion  must  be  poured  on 
very  slowly  in  order  to  obtain  a  thick  film.  This  is  much  better  than 
to  provide  the  plates  with  a  double  film  of  collodion,  as  unless  this  is 
done  with  extraordinary  skill,  the  second  application  of  collodion  will 
partially  dissolve  the  first.  Before  exposing  the  chloride  of  silver 
plates,  they  are  subjected  to  the  vapors  of  ammonia. 

"  The  ammonia  is  placed  in  a  watch-crystal,  which  is  placed  at  the 
bottom  of  a  box  provided  with  horizontal  grooves.  The  plates  are 
laid  three  or  four  inches  above  the  glass  containing  the  ammonia; 
they  are  exposed  for  three  minutes  to  the  vapors,  left  for  half  an  hour 
in  the  air,  and  placed  in  a  printing-frame  with  the  negative. 

"  Toning  and  fixing  are  done  according  to  the  directions  given 
abovp  " 


American  formula  for  collodio-chloride  of  silver. 

.  30  grammes. 
 30  " 


  0.625  " 

,    0.312  " 

r  calcium,    .       .       .0.25  " 

Nitrate  .       .       .       .    0.625  4 ' 

The  disf  *  'mts  are  the  same  as 


228 


THE  PRACTICE  OF  PHOTOGRAPHY. 


above.  (For  Krippendorf 's  receipts,  see  Vogel's  Pocket  Reference-book, 
page  217.    Ost's  receipt,  see  below,  Collodion  Paper.) 

%,  REPRODUCTION  OF  NEGATIVES. 

(a  }  By  means  of  the  Silver  Process. 

The  re  product"  negatives  depends  on  the  production  of  a  very- 
fine  transparent  uive  which  must  not  have  any  deposit  in  the 
shadows,  or  show  my  ^  ,ce  of  structure  or  grit.  The  former  chapter 
contains  all  the  p:  rticuiars.  The  process  in  the  camera  furnishes  a  pic- 
ture, which,  by  dean  -v^rkmanship,  and  right  time  of  exposure,  is 
serviceable  to  pi  ^due  .ood  negative.  The  albumen  process  fur- 
nishes, of  course  x  asitives.  The  exposure  being  in  the  printing- 
frame,  only  fiat  plates  are  necessitated.  The  collodio-chloride  of  sil- 
ver positives  are  not  intense  enough.  The  best  results  are  obtained  by 
the  dusting-in  process. 

Having  a  good  positive,  the  production  of  a  good  negative  presents 
no  difficulties.  If  it  is  to  be  as  large  as  the  original,  it  can  be  printed 
direct  from  the  positive  with  the  albumen  process;  if,  on  the  contrary, 
larger  or  smaller,  it  is  copfc  camera  according  to  the  process 

given  on  another  page,  in  t  t  manner.   The  skilful  operator, 

of  course,  will  carefully  retoucl)  4^  positive  previous  to  copying. 

(6.)  By  means  of  the  Dust  or  Powder  Process  of  Obemetter. 

Any  one  who  has  tried  the  process  of  reproducing  negatives  above- 
mentioned,  will  observe,  that  it  is  a  difficult  thing  to  obtain  a  nega- 
tive which  is  exactly  like  the  original,  possessing  the  same  sharpness, 
softness,  and  harmony.    Even  when  we  do  not  take  slight  variations 
into  account,  there  has  hardly  a  negative  been  made  which  could 
completely  replace  the  original.    The  reason  is,  probably,  that  for  the 
production  of  the  negative  two  processes  are  neces«^T 
duction  of  the  positive,  and  next  the  negp'  * 
with  chloride  of  silver,  or  with  the  came  Q 
The  relation  of  light  and  shade  becomes  d<     y  . 
tive,  and  when  we  take  a  negative  from 
will  occur,  and  the  consequence  is  tha+ 
considerably  from  the  positive. 

Obernetter  has  solved  tbe  pr^°  itive  by  em- 

ploying a  process  whicv  only,  i.  e.t  he 

makes  from  an-  1  pro- 


REPRODUCTION  OF  NEGATIVES. 


229 


cess  of  Poitevin.  This  process  was  improved  by  Obernetter  and  Zeu- 
bert,  arl'd  was  formerly  employed  for  making  porcelain  pictures.  A 
glass  plate  is  coated  with  a  film  of  gum,  grape-sugar,  and  chromate  of 
potash.  This  film,  when  dry,  is  somewhat  sticky,  so  much  so  that  a 
pigment  powder  when  dusted  over  it  adheres  to  it.  The  action  of 
light  destroys  this  stickiness,  and  when  the  film  has  been  exposed 
under  a  positive,  only  the  places  which  have  been  covered  by  the 
opaque  parts  will  retain  their  stickiness. 

If,  now,  after  exposure  a  powder  is  dusted  over  it,  it  will  adhere 
only  to  the  parts  which  have  not  been  exposed  to  light,  and  in  this 
way  we  obtain  a  positive  from  a  positive ;  of  course  a  negative  will 
yield  a  negative.  Obernetter  himself  has  practiced  this  process  for 
years  with  the  best  success,  and  transmitted  lately  to  the  Berlin  Pho- 
tographic Association  a  number  of  reproduced  negatives,  together 
with  the  originals.  The  former  were  such  exact  copies  that  only  a 
skilled  eye  could  detect  the  difference.  Obernetter  makes  it  a  busi- 
ness to  reproduce  negatives,  and  has,  in  fact,  made  excellent  w7ork  for 
Loescher  &  Petsch  here.  The  process  is  for  him  of  special  interest  in 
his  "  Lichtdruck  "  establishment,  where  he  has  to  work  with  reversed 
negatives,  in  order  that  the  resulting  pictures  may  appear  in  the  proper 
position.  Formerly  it  was  customary  to  detach  the  film  from  the 
glass,  and  to  reverse  it,  but  now  Obernetter  is,  by  the  abovementioned 
process,  enabled  to  make  a  reversed  negative,  because  the  reproduced 
negative  is  already  reversed,  and  can  therefore  be  used  for  the  "  Licht- 
druck "  directly.  When  a  negative  is  desired  in  which  the  position 
is  not  reversed,  we  pour  collodion  over  the  dusted  film,  and  after  it 
has  dried  we  place  the  plate  in  water;  the  film  soon  becomes  detached 
from  the  glass,  and  the  film,  with  the  picture,  can  easily  be  reversed, 
and  placed  on  glass. 

At  first  sight  it  looks  as  if  plate-glass  was  only  suitable  for  this  pur- 
pose, but  this  is  not  so.  Obernetter  has  copied  curved  negatives  by 
this  process,  and  it  is  not  at  all  difficult.  He  uses  mica  plates  for  the 
purpose,  which  he  coats  with  the  sensitive  composition.  These  con- 
form to  the  curved  plates,  and  after  the  picture  has  been  detached  it 
is  readily  transferred  to  glass.  Obernetter  has  already  reproduced 
two  thousand  negatives  for  the  "  Lichtdruck  "  up  to  a  size  of  two  feet. 
Another  advantage  is,  that  by  regulating  the  exposure,  we  have  it  in 
our  power  to  change  a  hard  negative  into  a  soft  one,  or  a  weak  one 
into  a  brilliant  one.  Obernetter  sent  me  original  negatives  and  copies, 
and  it  is  a  fact,  that  the  reproduced  negatives  give  finer  results  than 
the  originaL    The  Vienna  Society  has  awarded  to  the  inventor  the 


230 


THE  PRACTICE  OF  PHOTOGRAPHY. 


golden  Voigtlander  medal.  He  has  published  his  method  of  working, 
which  is  as  follows : 

Dextrin,  4  grains. 

"White  sugar,  5  " 

Bichromate  of  ammonium,       ....       2  " 

Water,   100  " 

Glycerin,   2-8  drops. 

The  above  materials,  after  being  dissolved,  are  filtered,  and  a  newly 
polished  piece  of  plate-glass  is  coated  with  it;  the  excess  is  poured  off 
from  one  corner,  and  the  plate  is  put  aside  to  dry.  If  the  plate  is  put 
into  a  drying-oven,  in  which  the  temperature  is  from  122-160  degrees 
Fahr.,  the  film  will  be  dry  in  from  five  to  ten  minutes ;  the  film  is  ex- 
posed under  the  negative  to  diffused  daylight  while  still  warm.  The 
exposure  lasts  for  about  five  to  fifteen  minutes,  according  to  the  den- 
sity of  the  negative  ;  when  the  picture  becomes  faintly  visible  the  ex- 
posure is  right.  After  exposure  the  plate  is  placed  again  in  the  dry- 
ing-oven until  it  is  a  little  warmer  than  the  air  of  the  room  in  which 
the  picture  is  to  be  developed.  The  development  should  take  place 
in  a  room  not  too  light.  The  plate  is  placed  upon  a  piece  of  white 
paper,  a  brush  is  placed  in  powdered  plumbago,  and  the  plate  is  care- 
fully brushed  with  it ;  by  breathing  on  the  plate  it  takes  the  plum- 
bago more  readily  (the  operation  is  somewhat  tedious  for  the  beginner, 
particularly  when  the  plate  has  been  somewhat  overexposed,  besides, 
the  plumbago-dust  makes  one  look  like  a  chimney-sweep).  When 
the  requisite  density  has  been  obtained  the  plate  is  dusted  off  and 
coated  with  a  plain  collodion,  containing  two  per  cent,  of  cotton  ; 
when  dry  a  sharp  knife  is  passed  around  the  margin,  and  the  plate  is 
placed  in  water.  The  film  is,  after  two  or  three  minutes,  easily  de- 
tached from  the  plate,  and  may  be  reversed  and  floated  on  a  plate  of 
glass.  The  plate  is  washed  under  a  gentle  stream  of  water,  in  order 
to  remove  air-bubbles  which  possibly  may  have  formed,  and  finally, 
solution  of  gum  (2  parts  gum  to  100  of  water)  is  poured  over  it,  and 
the  plate  is  left  to  dry,  spontaneously,  and  in  a  vertical  position. 

Obernetter  regulates  the  proportion  of  glycerin  according  to  the 
humidity  of  the  atmosphere.  When  the  air  is  damp  and  warm  no 
glycerin  is  necessary,  but  when  the  air  is  cold  and  dry  the  addition  of 
glycerin  is  advantageous.  In  America,  where  the  air  is  dry,  the  ad- 
dition of  glycerin  is  in  most  cases  to  be  recommended. 

The  plumbago  plays  a  very  important  part.  The  best  is  the  genuine 
Siberian,  finely  precipitated.  It  is  to  be  had  of  the  celebrated  Faber, 
at  Stein,  near  Nuremberg.  Obernetter  states  that  it  is  easy  to  guess 
'the  time  of  exposure.    Plates  which  have  been  exposed  too  short  a 


REPRODUCTION  OF  NEGATIVES. 


231 


time  become  veiled,  while  the  result  of  overexposure  is  a  hard  picture. 
I  must  remark,  that  guessing  at  the  time  of  exposure  is  a  rather  risky 
operation.  I  have  repeatedly  made  experiments,  but  always  in  vain; 
finally  I  resorted  to  the  photometer,  and  succeeded  admirably.  With 
thin  plates  I  copied  to  fifteen  degrees  ;  with  dense  ones  to  sixteen  de- 
grees ;  and  this  enables  one  to  be  entirely  independent  of  the  weather. 

W.  Woodbury  speaks  of  his  experience  in  reproducing  negatives 
as  follows :  On  my  late  visit  to  Germany,  I  saw  Obernetter's  repro- 
duced negatives,  and  these  induced  me  to  give  the  process  a  trial.  I 
obtained  very  good  results.  I  did  not,  however,  adhere  strictly  to  the 
instructions  of  the  formula,  i.  e.,  I  avoided  breathing  on  the  plates 
as  directed,  and  found  that  this  breathing  on  the  plate  was  the  cause 
of  all  failures.*  If  any  one  wishes  to  try  the  process,  I  would  advise 
him  not  to  breathe  on  the  plate,  except  in  such  cases  to  bring  out 
underexposed  parts  in  the  foreground.  It  is,  I  believe,  impossible  to 
moisten  the  plate  evenly  by  breathing ;  much  better,  if  necessary,  to 
place  the  plate  in  a  damp  place. 

I  used  the  following  solution  : 


Gum  arabic,  3.75  grammes. 

Grape-sugar,  3  " 

Glycerin,  .10  drops. 

Acid  chromate  of  potash,  ....  1.875  grammes. 
Water,   .   60  " 


Filter  while  warm  through  filtering-paper;  keep  in  a  bottle.  Cork 
is  unnecessary  ;  keep  covered  with  a  piece  of  glass  to  exclude  dust.  A 
glass  plate  is  washed,  dried,  and  carefully  dusted.  Every  particle  of 
dust  will  show  a  black  speck  in  the  negative.  I  cannot  say  how  long 
the  solution  will  keep ;  I  found  it  as  good  in  one  week  after  prepara- 
tion as  directly  afterwards.  But  as  the  solution  is  easily  prepared,  it 
is  unnecessary  to  keep  any  length  of  time.  One  obstacle  occurs,  when 
tilting  the  plate :  all  the  solution  flows  off  without  any  remaining  on 
the  plate,  especially  when  the  glass  has  been  cleaned  very  carefully. 
If  the  solution  is  applied  warm,  it  can  be  obviated.f 

The  plate  is  coated  in  the  usual  manner,  then  carefully  dried 
over  a  Bunsen  burner.  A  piece  of  blotting-paper  is  passed  over  the 
lower  edge  to  remove  all  thickening  of  the  solution  there.  After 
the  plate  is  dry  and  yet  warm,  place  it  in  contact  with  the  negative 
in  the  printing-frame,  and  expose  two  to  three  minutes  in  the  sun. 

*  In  the  dry  atmosphere  of  America,  breathing  on  the  plates  may  be  neces- 
sary, especially  in  dry  weather. 

f  We  avoided  this  by  breathing  on  the  glass. 


232 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Take  the  plate  out  of  the  frame,  leave  if  lay  about  five  minutes,  pass 
a  soft  pencil  dipped  in  graphite  over  the  plate,  and  distribute  it  until 
the  desired  intensity  is  obtained.  The  plate  is  then  coated  with  a 
thin  plain  collodion  and  dried,  after  which  it  is  placed  in  a  solution  of 
1  part  C.  P.  nitric  acid  and  6  parts  water,  which  dissolves  the  chro- 
mate.  When  the  negative  is  washed,  dried,  and  varnished,  it  is 
finished. 

I  must  give  a  few  special  rules.  The  negative  must  not  be  dusted 
until  it  is  as  dense  as  the  original,  as  it  will  print  too  harsh,  because 
the  graphite  is  not  as  transparent  to  light  as  silver.  Obernetter's 
reproduced  negatives  appear  much  thinner  than  the  original,  print- 
ing, however,  just  as  brilliant.  The  best  place  for  dusting  is  in  the 
cellar.  Freedom  from  dust  in  the  air  is  absolutely  necessary.  It 
further  requires  a  very  fine  graphite,  similar  to  that  used  for  coating 
galvano-plastic  forms.  It  is  better  to  apply  larger  glass  plates  than  the 
original  negative ;  there  will  be  no  danger  then  of  neglecting  the  edges 
while  dusting.  If  you  are  desirous  of  reversing  the  negative,  a  thicker 
collodion  is  necessary. 

SECTION  III. 

THE  TRANSFERRING  OF  PHOTOGRAPHS  TO  OTHER  SURFACES. 

At  times  photographs  on  ivory,  porcelain,  opaque  glass,  wood  (for 
the  production  of  woodcuts),  etc.,  are  desired.  These  are  produced 
with  the  ordinary  collodion  process,  and  the  film  transferred  from  the 
glass,  or  by  application  of  peculiarly  prepared  collodion  paper,  or 
transfer  paper. 

1.  TRANSFERRING  WITH  ORDINARY  COLLODION. 

Every  negative  or  positive  on  glass,  which  has  no  preliminary  coat- 
ing of  albumen,  can  be  stripped  off  the  glass,  by  pouring  on  the  un- 
varnished film  a  solution  of  1  part  of  caoutchouc  in  100  parts  of  ben- 
zine ;  after  drying,  coating  with  a  plain  collodion  containing  two  per 
cent,  of  cotton  and  one  per  cent,  castor  oil  (leather  collodion).  Throw 
the  plate  after  drying  in  water ;  the  film  can  be  removed  shortly,  com- 
mencing at  one  of  the  corners.  Another  manner  consists  in  pouring 
on  warm  gelatin  solution,  1 :  4,  in  a  horizontal  position,  and  drying. 
In  a  few  days  the  film  will  be  ready  to  come  off.  If  the  original  col- 
lodion is  thick,  it  can  be  slipped  off  by  immersing  in  acidulated 
water  (see  below).    For  negatives,  the  transferring  is  done  merely 


TRANSFERRING  OF  PHOTOGRAPHS. 


233 


to  be  able  to  print  from  the  other  side,  which  is  of  some  importance 
in  heliography,  photolithography,  etc.  The  mode  of  transferring  on 
wood  is  important  for  xylographs.  Grime  does  this  in  the  following 
manner.*  A  good  transparent  positive  is  made  in  the  camera  with 
the  ordinary  wet  process.  It  is  best  to  use  a  tough,  not  overiodized 
collodion.  Any  commercial  collodion  will  answer  to  which  has  been 
added  4  to  8  grammes  of  cotton  per  pound.  After  fixing,  the  plate 
is  left  in  the  water  about  half  an  hour — it  can  remain  several  hours 
without  injury — and  then  stripped  off  the  glass.  For  this  purpose  the 
plate  is  placed  in  a  dish  of  acidulated  water  (1  part  sulphuric  acid  to 
24  parts  of  water)  for  a  few  minutes;  bring  it  under  the  tap;  the  film 
is  then  easily  washed  off  into  a  dish,  which  must  be  ready  below.  The 
picture  is  now  toned,  which  in  this  case  is  easier  than  if  on  the  plate. 
The  tone  of  the  picture  is  of  some  importance  for  the  xylograph.  The 
color  must  have  a  good  contrast  from  the  ground,  at  the  same  time 
have  depth,  and  not  be  too  thick  and  intense.  A  gold  toning  bath 
will  answer  the  purpose,  requiring  more  thinning  down  than  for  albu- 
men paper.  A  solution  of  permanganate  of  potash  (2  parts  in  100 
water)  is  very  good,  furnishing  a  brown  picture.  A  chocolate-colored 
picture  is  obtained  with  Selle's  intensifier,  consisting  of  a  mixture  of 
ferrocyanide  of  potassium  and  nitrate  or  sulphate  of  uranium.  The 
toned  picture  is  placed  in  a  dish  of  clean  water.  It  is  not  exactly 
hard  to  work  with  a  detached  film ;  it  is  more  convenient  if  the  dish  is 
rather  deep.  Take  an  ordinary  camel's-hair  brush,  pass  it  under  the 
film,  pick  it  up  carefully  and  place  it  in  the  other  dish.  Should  the 
film  fall  together,  it  can  be  easily  smoothed  out  with  the  brush.  The 
film  is  now  placed  on  the  block,  which,  however,  must  be  previously 
prepared.  It  is  rubbed  with  zinc  white,  to  which  is  added  a  very 
small  quantity  of  gelatin,  just  enough  to  make  the  color  stick  without 
forming  a  film.  When  this  coloring  is  dry,  the  block  is  exactly  in  the 
condition  as  the  artist  generally  uses  it.  The  film  is  placed  on  the  block 
in  the  following  manner.  Take  a  clean  glass  plate,  hold  it  under 
the  floating  film,  pick  it  up  so  that  the  film  remains  upon  it.  Smooth 
it  out  with  a  camel's-hair  pencil.  The  whole  operation  is  not  diffi- 
cult; care,  however,  must  be  taken  that  the  picture-side  of  the  film  is 
on  the  glass.  A  piece  of  semi-transparent  paper  is  wetted  and  placed  on 
the  film,  so  that  it  will  overlap  the  paper  about  one-quarter  of  an  inch, 
which  is  turned  over.  The  paper  is  then,  with  the  film,  taken  off  the 
glass.  The  film  is  now  laid  on  the  block,  whereby  the  picture-side 
of  it  is  towards  it;  the  paper  is  then  removed.    As  the  paper  is  thin 


*  The  heads  of  Apollo,  in  Part  Third,  were  made  in  this  manner. 


234 


THE  PRACTICE  OF  PHOTOGRAPHY. 


and  transparent,  it  is  very  easy  to  bring  the  picture  into  right  position 
on  the  block.  Any  wrinkles  or  blisters  are  removed  with  the  camel's- 
hair  brush.  A  piece  of  blotting-paper  is  placed  on  the  film,  and 
gently  pressed  on  the  block,  at  the  same  time  removing  all  superfluous 
water.  When  the  film  has  superficially  dried,  alcohol  is  poured  on 
to  remove  all  traces  of  water.  The  film  is  then  dissolved  by  means  of 
alcohol  and  ether,  leaving  a  brown  or  black  picture,  consisting  of 
very  fine  metallic  powder,  fast  on  the  block.  The  dissolving  of  the 
film  is  necessary,  as  it  would  split  in  the  engraving.  If  the  negative 
is  taken  from  nature,  it  will  of  course  show  the  tone  but  not  the  tech- 
nicality of  a  woodcut.  Many  engravers  are  in  the  habit  of  translat- 
ing the  tones  into  lines,  and  find  no  difficulty  in  working  with  tones, 
but,  as  a  general  rule,  the  sketcher  must  produce  the  sketch  in  lines, 
which  the  engraver  must  engrave  accordingly.  It  would  be  advisable 
to  give  the  block  containing  the  photograph  to  an  artist  who  is  ac- 
customed to  this  work,  who  can,  with  a  few  strokes  of  a  lead-pencil,  in- 
dicate how  the  best  effect  can  be  obtained. 


SECTION  IV. 

ENLARGEMENTS. 

The  photographer  is  often  called  upon  to  furnish  an  enlarged  posi- 
tive from  a  small  negative.  This  can  be  accomplished  by  different 
methods. 

Photographic  pictures  directly  from  living  models  on  a  large  scale 
can  only  be  made  with  great  difficulty.  With  a  portrait  lens  of  long 
focus,  pictures  of  one-quarter  to  one-half  life-size  can  be  produced,  re- 
quiring, however,  a  long  exposure,  which  not  everybody  can  hold  out, 
the  sharpness  always  in  such  cases  suffering.  For  this  reason  large 
pictures  are  made  in  a  roundabout  way  by  taking  a  small  negative, 
enlarging  it  in  an  optical  manner.  The  small  negative  can  be  taken 
with  a  quick,  short-focussed  lens.  On  account  of  the  shortness  of  the 
focus  it  will  be  sharper  in  all  its  parts. 

Every  lens  forms  a  reduced  image  of  an  object  when  it  is  removed 
further  from  it  than  twice  the  focal  length.  When  an  object  is  nearer 
to  the  lens  than  twice  its  focal  length,  the  image  formed  by  the  lens 
will  be  enlarged. 

A  person  five  feet  high,  placed  at  the  distance  of  twenty  feet  from 
a  carte  de  visite  lens,  will  have  an  image  of  three  inches  in  height 
projected  on  the  ground-glass,  and  vice  versa,  this  same  lens  can  pro- 


THE  DIRECT  COPYING  PROCESS. 


235 


duce  a  life-size  picture  from  the  small  flat  negative  at  a  distance  of 
twenty  feet.  The  brightness  of  such  an  enlarged  image  decreases 
with  the  increase  of  surface,  and  it  is  evident  that  the  negative  which 
is  placed  at  the  focal  distance  from  the  lens  must  be  brilliantly 
illuminated  if  we  wish  to  obtain  a  bright  optical  image,  and  this 
illumination  should  be  the  more  intense  the  larger  the  desired  picture 
is  to  be. 

1.  THE  INDIRECT  PRINTING  PROCESS. 

This  will  answer  for  an  enlargement  of  six  to  eight  times.  For  this 
process  a  transparent  positive  in  the  camera  is  made,  or  with  collodio- 
chloride,  as  large  as  the  original  negative  (see  above),  and  from  this 
an  enlarged  negative.  This  enlarged  negative  can  be  made  in  the 
same  manner  as  the  positive  on  collodion.  However,  larger  plates 
than  three  feet  cannot  be  easily  made  for  this  reason ;  it  is  preferred 
for  medium  sizes.  It  can  also  be  printed  with  artificial  light,  and  de- 
veloped on  paper,  and  a  positive  printed  from  this  (see  above).  It 
must  be  remarked,  however,  that  the  first  transparent  positive  must  be 
carefully  retouched  before  making  the  subsequent  negative. 

2.  THE  DIRECT  COPYING  PROCESS. 

The  enlarged  image  is  projected  at  once  upon  sensitive  paper,  and 
either  printed  completely  or  brought  out  by  development.  In  the 
latter  case  a  feeble  light  will  suffice ;  in  the  former  a  very  intense 
illumination  of  the  negative  is  necessary,  and  this  is  accomplished  by 
the  rays  of  the  sun,  which  either  directly,  or  with  the  aid  of  a  reflector, 
fall  vertically  upon  the  negative.  In  both  cases  the  rays  are  concen- 
trated by  the  aid  of  a  large  condensing  lens.  Enlarging  apparatus 
has  been  constructed  for  this  purpose. 

Dependence  upon  solar  light  is  generally  a  great  drawback  to  this 
kind  of  work,  particularly  in  northern  latitudes,  where  the  rays  of  the 
sun  possess  but  feeble  power.  For  such  regions  the  employment  of  a 
printing  process  with  development  will  recommend  itself ;  of  course 
this  will  not  furnish  as  good  results  as  the  direct  printing. 

In  selecting  the  negatives  for  enlargement  it  must  be  observed  that 
every,  even  the  smallest,  fault  is  magnified,  and  hence  such  negatives 
must  be  real  ne  plus  ultras  as  regards  sharpness,  clearness,  softness, 
and  purity  of  the  glass.  It  is  customary  to  employ  negatives  for  the 
direct  copying  process  which  have  not  been  varnished,  as  the  deli- 
cate impurities  which  are  suspended  in  the  varnish  exercise  an  injuri- 


236 


THE  PRACTICE  OP  PHOTOGRAPHY. 


ous  influence,  besides  the  great  heat  of  the  concentrated  solar  rays  is 
apt  to  soften  the  varnish. 

For  moderate  enlargements  a  long  camera  of  large  dimensions  is 
sufficient ;  for  larger  sizes  it  is  better  to  use  a  dark-room  which  has 
especially  been  constructed  for  this  purpose ;  but  unless  there  is  a  great 
demand  for  these  pictures  its  construction  will  not  pay. 

3.  ENLARGEMENT  BY  DEVELOPMENT. 

There  are  two  different  ways  of  obtaining  a  large  positive  from  a 
small  negative.  The  direct  enlargement,  and  the  production  of  a  large 
negative  on  collodion  or  paper,  which  is  well  retouched  and  printed 
in  the  ordinary  manner. 

The  small  negative  which  is  to  be  enlarged  is  placed  in  the  appa- 
ratus ;  the  enlarged  image  is  projected  on  sensitized  bromo-iodized  al- 
bumen paper.  The  exposure  in  the  apparatus  requires  from  fifteen 
seconds  to  several  minutes,  in  fact  until  the  feeble  outlines  of  the  pic- 


ture appear.    The  following  bath  is  necessary : 

White  of  egg,  beaten  to  a  froth,  and  cleared,    .  100  parts. 

Distilled  water,   1000  " 

Iodide  of  potassium,   15  " 

Bromide  of  potassium,       .       .       .       .  15  " 

Or, 

Serum,       ........  1  ounce. 

Iodide  of  potassium,  ......  10  grains. 

Bromide  of  potassium,       .....  5  " 


The  paper  is  floated  on  this  bath  for  three  minutes,  dried,  and  pre- 
served in  a  closed  portfolio. 

For  sensitizing  it  is  floated  for  three  minutes  on  the  following 


silver  bath  : 

Distilled  water,   1000  parts. 

Nitrate  of  silver,   70  " 

Glacial  acetic  acid,   70  " 

While  still  moist,  the  paper  is  dipped  in  a  bath  of : 

Distilled  water,   1000  parts. 

Citric  acid,  4  " 

Pyrogallic  acid,  .......       2  " 


The  picture  develops  in  a  few  minutes ;  it  is  then  placed  in  a  bath 
of  hyposulphite  of  gold,  and  left  in  it  for  five  minutes,  and  washed. 


The  composition  of  the  fixing  bath  is  : 

Water,   1000  parts. 

Hyposulphite  of  soda, .       .....    100  " 

Chloride  of  gold,        ......       ^  l< 


THE  CARBON  PRINTING  PROCESS. 


237 


Generally  speaking  enlarged  pictures  are  inferior  in  beauty  to  those 
which  have  been  taken  directly.  In  America  I  have  seen  the  best 
solar  enlargements. 

The  whey  process  is  very  well  adapted  to  enlargements  by  develop- 
ing.   The  paper  is  immersed  in 

Iodide  of  potassium,  2  grammes. 

Bromide  of  potassium,  1  gramme. 

Filtered  whey,  100  grammes. 

Then  dried.  It  will  keep  for  some  time.  Before  using  it  is  sensitized 
on  a  bath  of 

Nitrate  of  silver,     .       .       .30  grammes  (in  winter  40). 
Water,   500  " 

Glacial  acetic  acid,  .       .     2  to  10  grammes,  according  to  tempera- 
ture, or  inclination  to  fog. 

Spread  it  out  damp  and  expose.  The  time  of  exposing,  in  the  solar 
camera,  is  fifteen  seconds  to  one  minute,  according  to  the  intensity  of 
the  negative. 

Developer. 

Pyro,  3  grammes. 

Glacial  acetic  acid,  .       .      %       .       .150  " 

Water,   1000  " 

Bromide  of  potassium,    .       .       .        1  to  2  " 

The  picture  is  developed  by  placing  it  on  a  glass  plate,  and  pouring 
on  the  solution.  To  prevent  too  strong  development,  pour  on  a  solution 
of  salt  afterwards. 


THE  CARBON  PRINTING  PROCESS. 

To  the  description  of  the  silver  printing  process  we  will  add  the 
process  for  making  carbon,  or  rather  pigment  pictures. 

They  have  only  recently  been  made  in  large  quantities.  As  re- 
gards their  ability  to  resist  chemical  influences,  and  also  the  choice 
of  color  (the  maker  can  give  to  the  gelatin  film,  which  is  the  founda- 
tion of  the  picture,  any  color  he  chooses  to  take)  they  offer  considera- 
ble advantages  over  the  silver  prints,  which  advantages  would  perhaps 
make  themselves  still  more  felt,  if  the  process  was  less  complicated. 

The  principle  of  the  process  consists  in  the  following :  Glue  or  gelatin 
mixed  with  chromate  of  potash  is  soluble  in  hot  water ;  exposed  to  the 
light  it  becomes  insoluble.  If  a  chromatized  film  of  glue  or  gelatin 
is  exposed  under  a  negative,  those  parts  through  which  the  light 
passes,  i.  e.,  the  shadows,  will  become  insoluble,  and  the  deeper  the 


238  THE  .PRACTICE  OF  PHOTOGRAPHY. 

longer  the  action  of  the  light  is  continued.  If  this  is  plunged  in  water, 
all  the  parts  which  were  not  exposed  to  the  light  will  dissolve,  and 
all  the  parts  exposed  to  the  light  will  remain,  giving  a  picture  of  the 
color  which  has  been  mixed  with  the  gelatin.  Generally,  the  surface 
only  becomes  insoluble,  and  the  part  underneath  remains  soluble.  If 
such  a  film  is  dipped  in  water,  the  lower  part  is  dissolved,  and  the 
upper  part  containing  the  picture  swims  away.  To  prevent  this,  the 
film  must  be  transferred  before  dipping  in  water  to  develop;  as  this 
reverses  the  picture  it  must  be  retransferred  after  developing. 

Pigment  paper  is  the  material  upon  which  the  prints  are  made. 
It  is  a  paper  coated  with  colored  gelatin,  and  can  be  bought  of  the 
stockdealers ;  two  kinds  are  mostly  used,  the  so-called  purple  black 
and  purple  brown.  It  should  be  kept  in  a  place  which  is  neither 
damp  nor  too  dry.    In  a  very  dry  place  the  gelatin  film  is  apt  to  break. 

Sensitizing  the  Paper. — The  sheet  which  is  to  be  sensitized  is 
placed  upon  a  glass  plate,  and  the  printing  surface  is  gently  rubbed 
with  a  soft  clean  linen  cloth.  Touching  the  paper  with  the  hands 
or  fingers  should  be  avoided  as  much  as  possible.*  After  being 
cleaned  it  is  seized  by  two  corners,  and  dipped  into  the  sensitizing  so- 
lution, and  by  drawing  it  through  it  it  is  skilfully  turned  and  left  in 
it  for  three  or  four  minutes  with  the  printing  surface  uppermost.  This 
must  be  done  by  lamplight.    The  sensitizing  solution  consists  of — 

30  parts  bichromate  of  potash. 
900  parts  cold  water. 

The  solution  will  not  keep  for  a  long  time,  and  it  is  best  not  to 
make  more  than  what  is  necessary  for  immediate  use.  For  a  sheet 
of  pigment  paper  about  250  cubic  centimetres  of  solution  are  neces- 
sary. The  solution  is  thrown  away  after  being  used.  The  necessary 
temperature  is  about  66°  Fahr.  Two  pieces  of  paper  can  be  placed 
at  once  into  the  solution,  but  they  must  be  kept  separated.  When 
deep  boxes  are  used  the  paper  can  be  placed  in  them  vertically,  and 
a  larger  number  can  be  sensitized  at  once,  but  they  must  be  kept 
about  one-half  of  an  inch  apart.  When  the  paper  has  been  taken 
out  of  the  bath  it  is  hung  up  to  dry,  by  fastening  two  corners  to 
strings  stretched  in  the  dark-room.  The  drying  temperature  must 
not  exceed  78°  Fahr. ;  when  it  is  higher  the  gelatin  is  apt  to  run  off. 
In  this  case  it  would  be  better  to  place  the  sheets  on  nearly  horizontal 
boards.  The  drying  requires  from  six  to  twelve  hours.  Paper  which 
has  been  sensitized  in  the  evening  is  ready  for  printing  the  next  morn- 


*  "With  fresh  clean  sheets  the  rubbing  is  unnecessary. 


THE  CARBON  PRINTING  PROCESS. 


239 


ing.  In  dry  weather  the  paper  will  keep  for  several  days,  in  damp 
weather  only  twenty-four  hours.  It  is  best  to  place  the  sensitized 
paper  into  a  book  with  a  weight  on  it ;  it  must,  of  course,  be  kept  in 
the  dark,  for  sensitized  pigment  paper  is  four  times  more  sensitive  than 
ordinary  silvered  paper. 

Exposure  of  the  Paper. — To  make  a  print,  the  perfectly  dry  paper 
is  placed  with  the  negative  into  the  printing-frame,  always,  of  course, 
by  lamplight. 

The  exposure  was  formerly  the  most  difficult  part,  but  the  intro- 
duction of  the  photometer  has  surmounted  this  difficulty,  and  made  it 
even  more  simple  than  the  silver  process,  as  not  all  the  frames,  but 
only  the  photometer,  has  to  be  examined.  A  person  not  experienced 
in  the  use  of  the  photometer  will  do  well  to  make  some  trials  with  it 
before  printing  a  picture  (see  remarks  thereon). 

Developing. — The  paper  which  has  been  exposed  shows  no  trace  of  a 
picture.  It  looks  black  as  before.  The  picture  appears  as  soon  as  it  is 
dipped  in  hot  water.  If  this  was  immediately  attempted,  a  picture 
without  half-tones  would  be  the  result.  For  this  reason  the  film  must 
be  transferred  from  its  original  support  (paper)  to  another  surface, 
glass  or  metal,  so  that  the  invisible  picture  on  the  surface  is  com- 
pletely lifted  off,  and  the  superfluous  gelatin  removed  from  the  back. 
If  the  picture  remains  on  this  new  surface,  it  will  appear  reversed ; 
transferring  again  will  bring  it  to  its  original  position.  If  it  is  wished 
to  have  the  picture  appear  glossy,  a  glass  or  smooth  zinc  plate  is 
rubbed  with  the  following  solution  : 

Gum  dammar,  .......      1  gramme. 

Benzine,    ........    40  grammes. 

If  a  more  gritty  surface  is  desired,  take  a  ground-glass,  zinc,  or 
porcelain  plate,  and  rub  it.  Instead  of  the  abovementioned  varnish 
for  the  same  purpose,  a  mixture  of  beeswax  and  resin,  equal  parts, 
dissolve  11  grammes  in  600  cubic  centimetres  of  turpentine.  Take 
off  the  surplus  poured  on  with  a  clean  rag,  so  that  the  surface  will 
not  appear  smeary.  If  a  pliable  support  is  desired,  rub  the  above  so- 
lution on  shellac  paper,  such  as  is  sold  by  the  Autotype  Company  of 
London. 

This  varnishing  is  only  necessary  when  the  picture  is  to  be  re- 
transferred.  If  it  is  to  remain  on  the  original  support,  very  often 
no  varnish  is  needed.  On  many  kinds  of  glass,  namely,  opaque  or 
milk-glass,  the  film  holds  well,  and  such  a  pigment  print  upon  it 
looks  wonderful,  the  main  object  being  to  have  the  plate  clean  and 
free  from  grease.    If  the  film  does  not  hold  by  itself,  the  varnish 


240 


THE  PRACTICE  OF  PHOTOGRAPHY. 


must  be  applied,  which  serves  afterwards  for  the  transferring  de- 
scribed below.  The  exposed  sheet  is  now  placed  in  cold  water,  and 
will  roll  directly  inwards ;  then  get  flat,  and  finally  roll  outwards.  As 
soon  as  it  is  flat  it  is  taken  out,  and  immediately  pressed  on  the  pre- 
pared surface;  dip  this  under  water,  and  squeeze  the  remaining  air- 
bubbles  out.  The  best  way  to  proceed  is  this  :  The  prepared  surface 
(glass  or  zinc)  is  laid  on  a  flat,  level  table,  water  poured  on,  the  sheet 
is  taken  out  of  the  tank  wherein  it  was  soaked,  holding  it  by  two  op- 
posite ends,  laying  the  middle  down  first,  letting  the  ends  down  gradu- 
ally, driving  thereby  all  the  remaining  water  out.  A  piece  of  gum  fast- 
ened between  two  pieces  of  wood  is  used  to  rub  the  remaining 
air-bubbles  out.  A  little  care  must  here  be  exercised,  as  they  will  not 
disappear  by  themselves.  The  plate  with  the  pigment  paper  is  now 
set  aside  for  five  or  ten  minutes;  it  is  then  dipped  in  a  tank  of  water 
of  about  25°  R.  In  a  short  time  the  paper  will  come  off,  and  the 
gelatin  dissolve  out.  The  paper  is  taken  away,  and  then  let  the  picture 
develop.  If  it  is  transferred  on  paper  it  is  best  to  turn  the  picture- 
side  down.  The  water  in  the  tank  had  best  be  kept  warm  by  a  lamp. 
When  the  picture  is  fully  developed,  rinse  it  off  with  cold  water. 
The  process  must  not  be  forced  too  much,  especially  do  not  use  the 
water  too  hot  at  the  commencement,  as  the  film  will  suddenly  ex- 
pand, and  become  full  of  wrinkles.  Beginners  must  also  be  careful 
not  to  let  the  sheet  expand  before  placing  on  the  zinc  plate,  and  not 
to  develop  too  soon  after  transferring.  If  the  picture  is  overexposed, 
use  finally  hot  water,  but  let  it  get  so  by  degrees.  When  the  picture 
is  washed,  it  is  made  insoluble  with  chrome  alum  solution. 

The  Transferring. — In  transferring  the  developed  picture  the  follow- 
ing papers  will  answer.  The  transferring  paper  of  the  London  Auto- 
type Company,  or  a  paper  prepared  with  the  following : 

Gelatin,   24  grammes. 

Chrome  alum,       ......  0.8  " 

Water,   576  " 

Glacial  acetic  acid,   12  " 

The  gelatin  and  alum  are  dissolved  separately,  are  then  mixed,  and 
the  acid  added  which  will  keep  the  solution  durable.  This  paper  is 
soaked  in  water  of  32°  R.,  the  developed  picture  is  moistened,  and 
brought  under  water  in  contact  with  it.  The  superfluous  water  is  re- 
moved by  squeezing  with  the  gum,  then  letting  it  dry.  The  paper  will 
come  off  the  picture.  The  transfer  paper  of  the  Autotype  Company 
is  better  than  the  above  receipt.  It  is  well  to  dip  the  finished  picture 
in  a  chrome  alum  solution  of  1  to  200,  and  dry.    It  is  pleasanter  to 


PIGMENT  PRINTS  ON  ALBUMEN  PAPER.  241 


obviate  the  second  transferring  altogether,  and  to  develop  the  picture 
on  the  original  surface.  Pigment  prints  transferred  on  toned  paper, 
the  high-lights  of  which  have  been  touched  with  Chinese  white,  have 
a  very  nice  effect.  By  transferring  to  gritty  or  rough -surface  paper, 
charming  effects  are  produced,  which  are  impossible  in  the  ordinary 
way  of  printing.  Finished  pigment  prints  can  be  colored  very  well 
with  water  colors.  If  it  is  desirable  to  color  heavy,  the  picture  is  pre- 
pared with  a  watery  solution  of  shellac  which  hardens  the  gelatin. 
Too  dark  parts  can  be  made  lighter  by  erasing. 

Printing  on  Ivory. — Pictures  can  be  transferred  directly  on  ivory 
and  developed,  and  this  is  recommended  instead  of  the  second  trans- 
ferring. With  gelatin,  of  course,  the  chrome  salt  colors  the  ivory 
yellow,  which  can  be  avoided  by  washing  the  picture,  thereby  remov- 
ing the  salt,  leaving  it  dry,  and  proceed  as  above.  It  is  well  to 
roughen  the  ivory  previously  with  a  piece  of  pumice-stone. 

Reversed  Negatives. — To  avoid  the  second  transferring  reversed  neg- 
atives must  be  used.  It  is  best  to  place  the  plates  reversed  in  the 
camera;  of  course,  the  focus  must  be  adjusted  to  the  thickness  of  the 
plate  used.    Prisms  can  also  be  used  to  reverse  the  pictures. 

PIGMENT  PRINTS  ON  ALBUMEN  PAPER 

Can  be  produced  on  coagulated  albumen  paper  very  easily.  Grass- 
hoff  and  Jeanrenaud  coagulate  their  albumen  paper  themselves,  by 
immersing  it  in  strong  alcohol  for  a  few  minutes,  and  drying.  It  is 
self-evident  that  in  this  manner  a  very  cheap  article  can  be  turned 
into  money.  The  damp  coagulated  albumen  paper  is  placed  on  a 
plate,  the  albumen-side  up.  Bring  the  exposed  pigment  paper,  which 
has  been  soaked  in  cold  water,  on  it,  and  press  it  on  well  to  remove 
all  air.  The  pictures  are  laid  in  a  press  for  about  one  hour,  and 
finally  dipped  in  hot  water  to  part  the  two  sheets.  The  pictures  now 
stick  to  the  albumen.  They  are  then  at  once  placed  in  lukewarm 
water,  and  fully  developed.  The  development  must  be  done  by  lamp- 
light. The  dried  pictures  are  tanned,  washed,  and  finished  as  usual. 
Jeanrenaud  remarks  that  alcohol  dissolves  the  resinous  sizing  of  the 
paper.  Marbled  stains  are  then  formed  on  the  transfer  paper,  and  if 
operated  after  transferring  into  hot  water,  blisters  appear  on  the  pic- 
ture. Jeanrenaud  obviated  this  difficulty  in  a  simple  manner.  The 
exposed  pigment  sheet  is  placed  in  a  pack  of  blotting-paper  which  is 
slightly  damp.  While  the  sheet  is  here  getting  pliable,  dip  the  albu- 
men paper  in  a  cylindrical-shaped  glass  which  is  filled  with  strong  al- 
cohol, draw  it  out  almost  immediately,  and  bring  the  alcohol-dripping 

16 


242 


THE  PRACTICE  OF  PHOTOGRAPHY. 


sheet  on  a  glass  plate,  albumen-side  up.  Now  take  the  pigment  paper, 
which  in  the  meantime  has  become  pliable,  lay  it  on  the  albumen  paper, 
and  press  it  on  by  means  of  a  leather  roller;  press  it  thoroughly  for  a 
few  moments  in  a  press,  and  develop  with  hot  water.  This  method  has 
several  advantages:  saving  of  alcohol  which  is  used  up  to  the  last 
drop ;  ease,  as  the  albumen  paper  can  be  prepared  the  moment  it  is 
wanted ;  avoidance  of  blisters,  even  when  boiling  water  is  used  ; 
saving  of  time.  If  the  sheets  are  properly  moistened  with  water,  it 
will  answer  to  put  them  together,  press  them,  and  develop  them  imme- 
diately. 

One  inconvenience  occurs  by  transferring  on  paper,  namely,  the 
forming  of  blisters  during  development.  These  are  caused  by  air, 
penetration  of  air  through  the  back  of  the  albumen  paper.  Vidal 
therefore  recommends  vegetable  paper  soaked  in  alcohol  instead  of 
albumen  paper,  which  is  impervious  to  air.  He  immerses  the  vege- 
table paper  for  fifteen  minutes  in  an  alcoholic  shellac  solution  contain- 
ing 12  per  cent,  shellac,  then  hangs  it  up  with  paper  pins  to  dry.  The 
pigment  print  is  fastened  in  a  similar  manner  as  on  a  zinc  or  glass 
plate,  and  afterwards  developed  in  warm  water.  The  picture  is  after- 
wards treated  with  alum.  It  can  be  transferred  from  the  shellac 
paper  to  a  second.  For  this  purpose  the  picture  is  coated  (lyiug  on  a 
glass  plate)  with  a  warm  gelatin  solution  (containing  15  per  cent, 
gelatin),  but  none  must  touch  the  back,  then  dry  the  whole.  After- 
wards the  sheet  to  hold  the  picture  is  slightly  moistened,  dried  with 
blotting-paper,  and  laid  on  the  film ;  all  traces  of  blisters  removed, 
afterwards  carefully  rolled  and  dried.  Finally,  throw  it  in  an  alcohol 
bath,  allowing  it  to  remain  for  one  hour.  The  shellac  sheet  will  soften, 
and  can  be  removed  with  a  penknife,  the  picture  remaining  on  the 
second  sheet,  in  the  original  position. 

THE  USE  OF  DR.  VOGEL's  PHOTOMETER. 

This  instrument  consists  mainly  (1)  of  a  semi-transparent  paper 
scale ;  the  transparency  of  this  scale  decreases  gradually  from  one  end 
to  the  other;  (2)  of  a  sensitive  chromate  paper,  which  will  retain  its 
sensitiveness  for  weeks.  The  paper  is  exposed  under  the  scale  in  a 
similar  manner  as  a  piece  of  silvered  paper  is  exposed  under  a  nega- 
tive. 

The  chromate  paper  is  made  by  dipping  plain  photographic  paper 
in  a  solution  of  one  part  of  red  chromate  of  potassium  to  thirty  parts 
of  water ;  when  dried  it  is  ready  for  use. 

The  dry  paper  is  cut  into  strips  of  suitable  size,  and  the  photometer 


THE  USE  OF  DR.  VOGEl/s  PHOTOMETER. 


243 


box,  2)  is  filled  with  them.  When  the  lid,  D,  of  the  box  is  closed,  a 
spring,  /,  presses  the  strips  against  the  transparent  scale.    The  scale  is 


Fig.  75. 


z 


fastened  to  the  glass  lid,  D,  and  can  be  held  in  contact  with  the  box, 
T,  by  the  hook,  Z. 

When  the  apparatus  is  exposed  the  light  will  pass  through  the  scale 
and  darken  the  strip  of  paper  underneath  it.  This  darkening  pro- 
gresses from  the  most  transparent  to  the  least  transparent  end  of  the 
scale,  and  the  progress  increases  in  rapidity  with  the  increase  of  the 
intensity  of  the  light. 

On  the  scale  black  numbers  are  painted,  in  order  to  ascertain  how 
far  the  action  of  the  light  has  extended.  The  opaque  numbers  do  not 
permit  the  light  to  pass  through  them ;  the  chromate  paper,  which 
gets  darkened  around  them,  will  show  a  white  number  on  a  brown 
ground. 

When  the  photometer  is  now  examined  by  lamplight  it  will  be  easy 
to  ascertain  (by  examining  the  strip  of  chromate  paper)  how  far  the 
action  of  the  light  has  extended,  as  the  last  visible  number  on  the  chro- 
mate paper  will  indicate  it. 

To  ascertain  the  proper  printing  time  of  a  negative  we  must  pro- 
ceed in  the  following  manner :  A  plate  containing,  for  instance,  four 
cartes  de  visite  negatives  is  exposed  to  the  light  simultaneously  with 
the  photometer ;  when  the  instrument  has,  for  example,  reached  the 
number  10,  one  of  the  four  pictures  is  covered  with  a  piece  of  black 
paper,  which  is  placed  between  the  negative  and  the  pigment  paper ; 
the  same  operation  is  repeated  when  the  number  12  has  impressed 
itself  on  the  chromate  paper,  and  so  on  when  it  has  reached  14  and 
16;  in  this  manner  the  different  pictures  have  been  respectively  printed 
to  10,  12,  14,  16. 

The  picture  is  developed  and  examined  to  see  which  part  shows  the 
proper  intensity.  The  degree  of  the  photometer,  for  this  part  of  the 
picture,  is  the  proper  degree  for  the  whole  negative. 


244 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Sometimes  the  proper  printing  degree  lies  between  two  of  the  num- 
bers employed,  for  instance  at  13  or  15 ;  when  this  is  the  case  the 
picture  marked  12  will  be  a  little  too  light,  while  14  is  a  little  too 
dark  ;  if  all  the  pictilres  are  either  over  or  under  printed,  the  experi- 
ment has  to  be  repeated  again  with  respectively  higher  or  lower  num- 
bers. 

With  large  pictures,  landscapes,  etc.,  a  similar  experiment  as  with 
a  carte  de  visite  negative  is  made  by  covering  successively  parts  of 
the  landscape,  taking  care,  however,  that  characteristic  parts — bright 
lights  and  dark  shadows — occur  in  every  part. 

A  number  of  negatives  are  arranged  according  to  their  density ;  the 
practical  photographer  will  easily  classify  them  by  looking  through 
them ;  they  are  assorted  in  three  classes — weak,  medium-dense,  and 
dense  ;  the  photometer  degree  for  each  class  is  determined  by  actual 
experiment,  and  all  the  pictures  are  printed  according  to  the  result. 

A  new  negative  is  closely  examined  with  the  eye,  and  compared 
with  a  negative  the  printing  degree  of  which  is  known,  and  the  print- 
ing time  is  regulated  accordingly. 

When  a  negative  should  offer  difficulties  in  determining  its  den- 
sity, an  experiment  is  easily  made ;  a  characteristic  part  of  the  pic- 
ture, under  which  a  strip  of  sensitive  paper  has  been  placed,  is  ex- 
posed to  the  light  simultaneously  with  the  photometer ;  the  strip  is 
gradually  covered,  when  the  photometer  has  respectively  shown  the 
numbers  10,  12,  and  14;  the  strip  is  then  transferred  and  developed, 
and  examined,  in  order  to  see  which  part  has  been  exposed  the  proper 
length  of  time. 

After  a  few  experiments  of  this  kind,  and  after  working  for  a  short 
time  with  the  photometer  and  the  pigment  printing  process,  the  eye 
becomes  so  well  trained  that  a  glance  at  the  negative  is  sufficient  to 
indicate  the  necessary  photometer  degree. 

For  the  purpose  of  printing  on  a  larger  scale  the  following  method 
is  the  must  practical :  All  the  printing-frames  which  one  intends  to 
use  are  filled  in  the  dark-room  with  paper ;  they  are  exposed  to  the 
sunlight  simultaneously  with  the  photometer ;  when  this  instrument 
indicates  the  printing  degree  of  the  weak  negatives,  the  latter  are 
taken  up  and  carried  into  the  dark-room,  or  they  are  reversed  and 
covered  up ;  and  so  on  with  the  medium-dense  ones  and  the  dense 
ones.  The  whole  operation  will  in  fine  weather  only  take  a  few 
minutes.  The  photometer  must  be  watched  very  closely,  in  order  to 
arrest  the  printing  process  at  the  very  moment  when  it  has  progressed 
far  enough.  When  all  the  frames  have  been  taken  into  the  dark- 
room they  are  refilled  with  fresh  paper,  and  the  process  begins  anew. 


THE  USE  OF  DR.  VOGEL's  PHOTOMETER.  245 


When  the  saving  of  time  is  an  object,  and  where  not  a  minute  is  to 
be  lost,  three  photometers,  one  for  each  class  of  negatives,  should  be 
employed. 

The  next  thing  to  be  taken  into  account  is  the  sensitiveness  of  the 
pigment  paper ;  American  paper,  for  instance,  is  twice  as  sensitive  as 
English  paper. 

When  the  photographer  receives  a  paper  the  sensitiveness  of  which 
differs  from  that  with  which  the  photometer  degrees  have  been  de- 
termined for  his  negatives,  a  new  experiment  becomes  necessary,  and 
the  result — the  difference  in  sensitiveness  expressed  in  photometer  de- 
grees— can  easily  be  added  to  or  deducted  from  the  negatives,  as  the 
case  may  be. 

By  a  single  trial  (as  described  above)  the  degree  of  a  single  negative 
is  determined  for  the  new  paper.  When  for  the  old  paper  the  degree 
of  a  negative  is,  for  instance,  12,  and  for  the  new  paper,  say  14,  it 
only  remains  to  add  simply  the  difference,  14 — 12  =  2,  to  all  the 
known  degrees  of  the  old  negatives,  and  they  will  by  this  simple  pro- 
cess be  correctly  timed  for  the  new  paper. 

When  the  new  paper  has  a  lower  degree,  10,  for  instance,  then  the 
difference,  12 — 10,  is  deducted  from  all  the  known  degrees. 

The  photometer  paper  is  prepared  in  the  following  manner : 

A  sheet  of  plain  Rives  or  Steinbach  paper  is  cut  up  into  eight  equal 
parts,  and  immersed  by  lamplight  for  three  minutes  in  a  solution  of 

1  part  of  bichromate  of  potash, 
30  parts  of  water. 

It  is  the  same  solution  with  which  the  pigment  paper  is  sensitized. 
The  strips  are  completely  immersed,  and  hung  up  to  dry. 

Paper  prepared  in  this  manner,  kept  in  dry,  clean  wooden  boxes, 
from  which  the  light  is  excluded,  will  keep  for  at  least  four  weeks  with- 
out change. 

The  photometer  paper  should  be  made  before  the  pigment  paper 
is  sensitized  in  the  liquid ;  after  it  has  served  for  the  latter  purpose, 
it  is  no  longer  fit  for  the  photometer. 

The  paper  is  cut  into  strips  of  suitable  size  to  fit  into  the  photometer 
box  ;  the  fingers  should  be  perfectly  dry  while  handling  it.  The  first 
and  last  strips  are  thrown  away.  The  strips  are  laid  one  by  one  into 
the  open  photometer  box ;  the  press  board  is  placed  in  position,  and 
the  lid  is  closed  with  the  spring.  The  upper  glass  lid  is  now  opened, 
by  lamplight,  in  order  to  ascertain  if  everything  is  smooth  and  even. 
The  papers  must  be  firmly  pressed  between  the  strips  of  tin.  When 
everything  is  not  smooth  and  even,  it  is  easy  to  make  it  so  by  means 


246 


THE  PRACTICE  OF  PHOTOGRAPHY. 


of  a  piece  of  white  paper,  which  is  introduced  from  the  glass  lid,  and 
smoothed  with  the  finger.  All  this  must  of  course  be  done  by  lamp- 
light. 

When  everything  is  in  proper  order  the  box  is  closed  and  hooked. 

So  prepared,  the  photometer  with  the  lid  closed  is  placed  in  posi- 
tion simultaneously  with  the  covered  printing-frames ;  next  the  cover  is 
removed  from  the  frames,  the  lid  of  the  photometer  is  opened,  and  the 
exposure  begins.  After  a  short  time,  say  from  one  to  five  minutesj 
according  to  the  weather,  the  frames  are  covered  again,  the  lid  of  the 
photometer  is  closed,  and  the  latter  is  carried  into  the  dark-room, 
where  a  lamp  is  burning. 

The  instrument  is  here  opened  and  examined,  in  order  to  see  which 
figures  have  appeared.  No.  2  appears  first,  bright  on  a  brown  ground, 
next  4,  then  6,  etc. ;  the  higher  figures  of  course  much  paler.  In  order 
to  ascertain  how  far  the  action  of  the  light  has  progressed,  it  is  neces- 
sary to  protect  the  eyes  against  bright  light. 

The  open  instrument  is  held  below  or  at  the  side  of  a  bright  flame, 
at  about  the  distance  of  eighteen  inches,  in  such  a  manner  that  the 
rays  fall  vertically  upon  the  yellow  paper.  With  the  eye  protected 
against  the  light,  we  glance  over  the  paper  (in  the  direction  of  the 
figures  from  2  to  25).  When  held  in  this  position  it  is  easy  to  discern 
the  figures.  But  not  only  should  the  attention  be  directed  to  the 
figures,  but  also  to  the  index  hands  and  letters,  as  they  materially 
facilitate  the  recognition  of  the  slightest  light  effect  on  the  paper. 
Turning  the  instrument  gently  from  side  to  side  will  soon  enable  one 
to  ascertain  the  most  advantageous  position. 

After  a  few  experiments  the  necessary  expertness  is  readily  acquired. 

It  must  be  observed  that  when  one  steps  from  a  light  room  into  a 
dark  one,  that  at  first  nothing  will  be  noticed,  but  the  eye  soon  ac- 
commodates itself  to  the  dim  light,  and  we  are  able  to  recognize  all 
the  details. 

Similar  things  occur  when  we  try  to  read  the  photometer,  and 
when  the  eyes  are  dazzled  by  bright  light. 

When  the  observation  is  over,  the  photometer  is  returned  to  its 
place  amongst  the  printing-frames ;  the  lid  is  opened,  the  frames  are 
uncovered,  and  the  exposure  is  continued.  After  one  or  more  minutes, 
the  photometer  is  carried  back  into  the  dark-room  and  re-examined, 
having  previously  covered  the  frames,  observing  all  the  precautions 
enumerated  above.  When  the  desired  degree  has  not  been  reached, 
the  exposure  is  continued.  The  time  which  has  so  far  elapsed,  and 
the  figures  which  have  been  observed,  serve  as  a  guide  for  calculating 
how  much  more  time  may  be  necessary  to  finish  the  print. 


THE  USE  OF  DR.  VOGEL's  PHOTOMETER.  247 


Exceeding  the  number  by  a  single  degree  does  not  amount  to  much, 
as  the  error  is  easily  remedied  by  longer  development.  Under-ex- 
posure is  worse. 

When  we  have  negatives  of  different  degrees,  we  have  first  to  re- 
move those  of  lower  degree,  or  wTe  may  cover  them  up,  and  continue 
the  exposure  of  the  balance  until  their  proper  degrees  have  succes- 
sively been  reached. 

When  all  the  prints  have  been  made,  the  frames  are  carried  into 
the  dark-room  ;  the  frames  are  supplied  with  fresh  paper,  and  the 
upper  yellow  colored  strip  is  taken  from  the  photometer  by  pressing 
upon  it  with  the  thumb  of  the  left  hand;  this  lowers  the  spring  lid  ;  both 
ends  of  the  strip  are  now  pulled  from  under  the  tins  ;  the  remaining 
strips  are  smoothed  down,  and  after  closing  the  instrument,  it  is  ready 
for  another  exposure.    The  upper  yellow  strip  is  thrown  away. 

Photometer  observations  require  the  same  qualities  which  every 
silver  printer  should  have  when  he  wants  to  make  silver  prints : 

1.  An  eye  which  can  discern  slight  light  effects. 

2.  Care  in  regard  to  the  photometer  paper.  The  latter  is  more  sensi- 
tive than  silvered  paper,  and  should  be  treated  with  the  same  cleanli- 
ness ;  it  must  not  be  exposed  to  bright  daylight.  Particularly  in  clear 
weather  great  care  is  necessary. 

If,  through  carelessness,  the  paper  becomes  affected  by  daylight,  it 
loses  part  of  its  sensitiveness.  We  must  also  remark  that  in  the  lower 
degrees  the  instrument  rises  very  rapidly ;  in  the  higher  ones  much 
slower. 

It  is  further  to  be  observed  that  the  paper  scale  must  be  firmly 
pressed  against  the  yellow  strip,  as  much  so  as  the  silvered  paper  has 
to  be  firmly  pressed  against  the  negative. 

The  paper  scale  must  not  be  touched  with  the  fingers,  and  must  be 
kept  dry.  The  glass  should  always  be  cleaned  previous  to  using  the 
instrument. 

I  mention  the  following  degrees,  for  a  negative  of  medium  density, 
as  determined  by  trial,  for  different  kinds  of  pigment  paper : 

Paper  by  Swan  (brown-black),      .       .       .       .15  degrees. 
"       Kowell  (gray-black),       .       .       .       .11  " 
"       Beyrich  (purple-black),  ....    12  " 
"       Beyrich  (purple-brown),  .       .       .       .16  ££ 


248 


THE  PRACTICE  OF  PHOTOGRAPHY. 


SECTION  V. 
FERROTYPES. 

Instead  of  the  ceremonious  negative  and  positive  process,  the 
Americans  often  make  use  of  the  ferrotype  process,  which  produces  a 
positive  picture  direct  in  the  camera.  If  a  negative  is  held  against  a 
dark  background  it  will  appear  positive.  The  shadows  are  formed 
by  the  dark  background  which  is  visible  at  the  transparent  parts,  the 
lights  by  the  silver  which  covers  them.  In  an  ordinary  negative  the 
lights  are  covered  too  heavily,  showing  therefore  no  detail.  If,  how- 
ever, a  negative  is  under-exposed,  a  glass  picture  is  obtained  which 
on  black  paper  has  a  very  good  positive  effect.  Such  pictures  can  be 
made  on  an  asphalted  iron  plate,  which  itself  furnishes  a  dark  ground. 
Such  iron  plates  are  collodionized,  silvered,  exposed  a  little  short,  de- 
veloped, fixed,  and  varnished,  furnishing  in  a  short  time  a  positive  pic- 
ture, which  of  course  shows  the  right  left,  and  the  left  at  the  right, 
and  vice  versa.  The  chemicals  necessary  to  this  process  do  not  ma- 
terially differ  from  the  negative  process.  For  a  silver  bath  a  nega- 
tive bath  with  a  few  more  drops  of  nitric  acid  per  pint  will  answer. 
For  collodion,  one  with  considerably  less  salt  and  cotton  than  in  the 
negative  process  is  used.  Trask,  in  his  excellent  "  Practical  Ferro- 
typer,"  recommends : 

Bromide  of  potassium,   20  grains. 

Bromide  of  cadmium,       .       .       .       .       .       .  30  " 

Iodide  of  ammonium,   100  " 

Ether  and  alcohol,   10  ounces. 

Gun-cotton      to  5  grains  per  ounce. 

Any  freshly  prepared  developer  is  to  be  recommended.  For  fixing, 
use  cyanide  of  potassium ;  it  makes  the  shadows  clearer. 

As  full  instructions  with  formulae  for  making  ferrotypes  are  given  in 
the  Ferrotyper's  Guide,  I  must  refer  my  readers  to  its  pages  for  further 
information. 


PRACTICAL  APPLICATION  OP  PHOTOGRAPHY. 


249 


CHAPTER  VII. 

PRACTICAL  APPLICATION  OF  PHOTOGRAPHY. 

In  the  previous  part  of  my  work,  I  have  explained  the  operations 
which  are  necessary  for  the  production  of  a  negative  or  positive  pic- 
ture by  means  of  light,  without  reference  to  the  nature  of  the  object 
to  be  taken. 

Any  one  who  will  follow  exactly  the  directions  given,  may  take 
whatever  object  he  pleases,  and  will  always  get  a  picture,  but  very 
seldom  a  perfect  one.  Even  the  beginner  will  soon  find  out  that  the 
nature  of  the  object  has  a  great  deal  to  do  with  success,  and  that 
this  should  not  be  overlooked  when  we  wish  to  obtain  a  satisfactory 
result. 

Let  us  attempt  to  copy  an  oil  painting,  or  a  copperplate  print,  with 
an  exposure  which  would  be  sufficient  for  a  portrait,  or  the  reverse ; 
let  us  apply  the  intensification  which  is  necessary  for  such  repro- 
ductions to  a  portrait,  or  let  us  copy  a  large  drawing  with  an  illumi- 
nation suitable  for  a  portrait.  In  either  case  we  will  be  horrified  at 
the  result. 

The  nature  and  the  succession  of  the  operations  remain  generally 
speaking  the  same,  and  still  every  one  of  them,  pose,  illumination,  se- 
lection of  the  model,  sharp  focussing,  time  of  exposure,  development,  in- 
tensification, must  in  some  measure  be  modified  according  to  the  nature 
of  the  object  to  be  taken,  and  unless  we  pay  strict  attention  to  these 
circumstances  the  resulting  picture  will  not  be  satisfactory. 

It  is  erroneous  to  think  that  photography  always  draws  truly.  Noth- 
ing can  be  less  true  than  a  photograph,  when  it  has  been  made  under 
circumstances  which  are  not  suitable  for  the  object.  (See  chapter  on 
^Esthetics.) 

We  must  therefore  go  a  little  more  into  detail  concerning  photo- 
graphic operations  as  applied  to  different  objects. 

The  field  is  endless.  Sun,  moon,  and  stars,  animals,  plants,  min- 
erals, products  of  art  and  products  of  nature,  the  microcosmus  and  the 
macrocosmus,  all,  all  belong  to  the  realm  of  photography.  So  I  am 
excusable  when  from  the  multitude  of  things  I  only  make  a  selection. 
To  treat  of  all  exceeds  the  limit  of  our  work. 

I  will  select  those  objects  the  representation  of  which  is  principally 


250 


THE  PRACTICE  OF  PHOTOGRAPHY. 


the  work  of  the  practical  photographer, — drawings,  paintings,  models, 
machinery,  architectural  objects,  landscapes,  and  portraits. 

I  will  speak  first  of  the  more  mechanical  work  .of  "  reproductive 
photography"  and  the  copying  of  technical  objects,  and  I  will  reserve 
the  consideration  of  portrait  and  landscape  photography,  which  is 
more  of  an  artistic  character,  for  the  second  part  of  my  work. 

SECTION  I. 

PHOTOGRAPHIC  REPRODUCTIONS. 

{Copying  of  drawings,  prints,  oil  paintings,  etc.,  etc.) 

1.  PREPARATION  OF  THE  ORIGINAL. 

Care  should  be  taken  to  get  a  clean  original.  A  drawing  with 
dirty  finger-marks  will  yield  a  dirty  negative.  Lead-pencil  lines  in 
india-ink  drawings  are  also  annoying,  and  unequal  color  of  india-ink 
is  objectionable.  Photography  reproduces  everything,  the  most  trifling 
thing,  and  the  latter  very  often  in  an  unpleasant  degree.  Drawings 
and  prints  should  first  be  rolled  in  the  press,  to  do  away  with  the  ine- 
qualities of  the  paper.  Pictures  which  are  framed  under  glass  should 
be  taken  out  of  the  frames,  as  the  glass  is  apt  to  produce  disturbing 
reflections  of  light. 

It  is  well  known  how  much  difficulty  some  yellow  prints  or  spotted 
drawings  will  cause.  To  overcome  this,  we  should  resort  to  retouch- 
ing the  original.  Mr.  Scamoni,  photographer  in  the  Imperial  printing 
establishment,  at  St.  Petersburg,  writes  about  it  as  follows :  Every  yel- 
lowish or  otherwise  disturbing  spot  is  carefully  covered  in  the  spaces 
between  the  lines  with  flake  white,  and  the  shadows  are,  wherever  it  is 
possible,  intensified.  When  the  paper  is  rumpled  and  not  smooth,  it 
should  be  firmly  pressed  in  a  frame  against  a  piece  of  plate-glass, 
through  which,  when  it  is  carefully  placed,  and  with  a  steady  light, 
very  good  photographs  can  be  taken.  That  the  object  be  absolutely 
plane  is  always  necessary,  otherwise  the  picture  will  show  distortion.  . 

2.  ARRANGEMENT. 

The  reproduction  of  drawings  is  the  simplest  of  photographic  work. 
Elaborate  arrangements  are  unnecessary.  Perfectly  smooth  stretching 
on  the  drawing-board,  perfect  parallelism  between  the  board,  the 
ground-glass,  and  the  apparatus,  are  the  principal  conditions  of  suc- 
cess. When  these  conditions  are  not  observed,  distortions  in  the 
drawing  will  necessarily  be  the  consequence.    The  lines,  which  are 


ARRANGEMENT. 


251 


parallel  amongst  themselves,  converge  towards  the  top  or  the  sides, 
when  the  apparatus,  instead  of  being  absolutely  vertical  to  the  axis  of 
the  drawing,  is  turned  a  little  upwards,  or  downwards,  or  sideways. 

To  secure  this  parallelism  in  the  position,  larger  establishments  have 
made  arrangements  to  keep  drawing-boards  and  apparatus  always 
parallel  to  one  another. 

Such  an  apparatus  (Fig.  76)  consists  of  a  strong  support,  which 
rests  lengthways  on  four  or  more  feet.    On  one  end  the  drawing-board 


Fig.  76. 


is  attached  at  right  angles  to  the  metal  guides,  which  are  fastened  to 
the  sides  of  the  support,  and  along  which  the  camera  moves.  When 
necessary,  one  end  can  be  left  open  to  admit  the  operator  for  the  pur- 
pose of  focussing,  and  the  support  can  be  made  rigid  by  uniting  the 
feet  near  the  floor,  and  strengthening  the  guides  on  which  the  camera 
moves,  by  iron  braces.  On  the  copying-table  in  the  Royal  Techni- 
cal Institute,  in  Berlin,  the  drawing-board  is  moved  by  cords,  which 
run  over  rollers  underneath  the  camera. 

The  drawing-board  should  be  divided  into  square  inches,  which, 
combined  witji  the  square  inches  which  are  marked  on  the  ground- 
glass,  will  be  a  great  help  in  determining  whether  the  picture  is 
exactly  square  and  of  the  right  shape,  and  it  affords  at  the  same  time 
a  means  for  determining  the  proportion,  whether  i,  or  i.  It  is 
also  very  practical  to  provide  this  apparatus  with  a  scale  at  the  sides 
divided  into  inches,  by  which  the  distance  between  the  drawing  lens 
and  ground-glass  can  be  determined  beforehand.  The  distance  (with 
a  given  lens)  necessary  for  making  a  natural  size,  double  natural  size, 
or  half  size  picture,  can  be  marked  down  once  and  forever,  and  all 
the  trouble  of  finding  out  the  position  is  avoided  in  the  future. 

The  dimensions  of  these  supports  must  necessarily  depend  on  the 
extent  of  business  of  the  atelier.  It  must  be  observed  that  for  natural 
size  drawings,  the  ground-glass  must  be  removed  from  the  lens  the 
distance  of  twice  its  focal  length.    Smaller  supports  of  this  kind 


252 


THE  PRACTICE  OF  PHOTOGRAPHY. 


should  be  placed  on  rollers,  as  it  facilitates  their  removal  from  place 
to  place. 

In  an  atelier  where  reproductions  are  an  exception,  simpler'  arrange- 
ments will  answer  every  purpose. 

In  this  case  the  drawing  is  simply  placed  on  a  stand  as  before 
described,  and  the  camera  is  placed  opposite.  The  distance  necessary 
for  getting  the  correct  size  of  the  picture  is  first  found  approximately; 
next  the  board  and  camera  are  placed  as  nearly  vertical  as  possible  by 
placing  the  sides  exactly  parallel  with  some  vertical  architectural 
part,  as,  for  instance,  the  corner  of  a  room ;  finally,  to  get  the  camera 
and  board  parallel  to  one  another,  the  lines  of  the  boards  of  the  floor 
will  serve  as  guides.  It  requires  some  patience,  but  the  result  is  better 
than  with  a  spirit-level. 

A  very  simple  method  to  place  the  camera  and  copying-board  par- 
allel, consists  in  using  a  black  board  with  a  white  stick  fastened  to 


Fig.  77. 


it  perpendicularly.  This  is  fastened  on  the  copying-board  ;  point  your 
camera  towards  it  and  focus ;  if  the  stick  appears  as  a  white  circle  on 
the  ground-glass,  the  camera  and  board  are  parallel. 

With  oil  paintings  a  different  course  has  to  be  taken  ;'to  avoid  glar- 
ing reflections,  they  have  to  be  inclined  forward  in  the  same  way  as 
they  are  generally  hung  on  the  walls  of  galleries.  • 

3.  ILLUMINATION. 

For  copying  drawings,  the  illumination  is  of  the  simplest  kind  ; 
nothing  is  necessary  but  an  even  light  over  the  whole  surface.  This 
takes  place  only  when  the  angle  of  light  is  nearly  the  same  for  every 
point  of  the  picture.  Any  one  who  has  studied  the  principles  of  illu- 
mination, as  laid  down  previously,  will  easily  satisfy  himself  on  this 
point.  A  front  light,  which  passes  over  the  camera  on  to  the  drawing, 
is  the  best.  Care  should  be  taken  that  the  camera  does  not  throw  its 
shadow  on  the  drawing. 


THE  LENS. 


253 


Sometimes  the  paper  is  rough ;  each  fibre  or  each  depression  will 
cause  a  shadow.  When  this  is  the  case,  the  drawing  should,  if  possi- 
ble, be  passed  through  the  rolling  press,  or  else  a  sheet  of  white  paper 
should  be  laid  in  front  of  it  and  used  as  a  reflector. 

More  aunoying  than  unevenness  is  gloss,  as  with  varnished  pictures, 
and  particularly  oil  paintings  and  photographs.  The  easel  with  the 
picture  should  be  placed  where  this  disturbing  reflection  does  not  ap- 
pear. Opening  and  closing  the  curtains  sometimes  gives  material 
advantages.  To  be  quite  sure  that  it  does  not  disturb,  the  eye  should 
be  placed  in  front  of  the  lens  and  the  picture  examined.  This  will 
show  the  exact  effect  of  illumination.  Oil  paintings  are  placed  at  an 
angle,  as  stated  above ;  the  axis  of  the  apparatus  is  placed  vertical  to 
the  surface.  Sometimes  direct  sunlight  is  of  advantage,  particularly 
when  age  has  darkened  the  picture.  The  illumination  should  be  so 
arranged  that,  besides  the  gloss,  the  shadows  of  heavy  layers  of  paint 
are  avoided. 

4.  THE  LENS. 

All  kinds  of  lenses  are  used  for  reproductions.  With  art  subjects, 
copperplate  prints,  oil  paintings,  a  slight  distortion  does  not  matter 
much,  particularly  when  only  the  central  part  is  used.  For  mathe- 
matically correct  pictures,  however,  an  absolutely  correct  drawing 
lens  is  required,  and  as  such  a  one  I  recommend  the  Steinheil  Apla- 
natic  Lens,  or  the  Ross  Doublet. 

Portrait  lenses  which  have  a  great  deal  of  light  are  only  necessary 
for  dark  oil  paintings,  to  shorten  the  time  of  exposure.  Objectives  of 
feeble  light,  as  the  Pantoscope  (which  also  draws  correctly),  can  only 
be  employed  with  a  bright  light. 

With  the  full  opening,  the  lens  is  focussed  on  the  centre  of  the  pic- 
ture (with  the  Steinheil  lens),  or  half  way  between  centre  and  margin 
(with  the  Doublet  lens)  ;  after  this  has  been  done  the  stops  are  inserted. 
For  line  drawings,  a  stop  should  be  used  so  small  that  the  picture  is 
sharp  to  the  edge.  For  oil  paintings,  larger  stops  should  be  used,  to 
gain  light. 

5.  PROTECTION  OF  THE  OBJECTIVE  AGAINST  FOREIGN  LIGHT. 

This  protection  is  absolutely  necessary  for  drawings,  where  it  is  the 
object  to  obtain  clear  lines.  A  black  box,  and  a  piece  of  pasteboard 
in  which  a  hole  has  been  cut,  just  large  enough  to  show  the  drawing, 
but  excluding  everything  else,  is  placed  in  front  of  the  lens.  A  wide 
tube  placed  over  the  objective,  in  which  another  tube  moves,  like  a 


254 


THE  PRACTICE  OF  PHOTOGRAPHY. 


telescope,  is  also  of  advantage.  Landscape  lenses  do  not  require  this 
protection  as  much  as  portrait  lenses. 

The  whole  field  of  view  of  the  lens  should  not  be  used,  as  this  would 
expose  one  to  a  considerable  loss  of  light  towards  the  margins. 

6.  TIME  OF  EXPOSURE. 

The  correct  time  of  exposure  is  not  so  easily  determined  in  repro- 
ductions. We  must  distinguish  between  black  line  drawings  without 
half  tones,  copperplate  prints,  and  pictures  with  half  tone.  When 
the  former  are  exposed  too  short  a  time,  the  picture  develops  slowly 
and  looks  pale;  all  the  lines  are  transparent,  and  it  requires  long  in- 
tensifying, and  the  film  is  apt  to  become  brittle  and  to  split.  When 
the  exposure  is  too  long,  the  black  lines  will  finally  exert  some  action, 
and  will  appear,  after  development,  weak  and  foggy;  they  will  print 
gray  instead  of  black.  Generally  speaking,  in  line  drawings,  over- 
exposure is  worse  than  under-exposure ;  just  the  reverse  from  land- 
scape or  portraits. 

Drawings  with  half  tones  require  longer  exposure  than  line  draw- 
ings, in  order  to  get  details  in  the  shadows.  Drawings  with  halftones 
and  lines  give  the  greatest  difficulty.  When  we  expose  for  half  to?ies, 
we  get  partially  veiled  lines;  when  we  expose  a  shorter  time,  the  lines 
will  be  black,  but  the  half  tones  will  be  hard,  and  the  shadows  will 
be  wanting  in  detail.  Of  the  two  evils,  we  should  choose  the  least. 
Draughtsmen,  who  work  for  photographers,  should  accustom  them- 
selves to  drawing  with  deep  black  lines  on  white  paper.  Gray  lines 
give  the  most  trouble ;  for  instance,  the  glossy  lead-pencil  line. 
Copperplate  prints  also  cause  some  difficulty ;  generally  they  are  only 
medium  black,  and  we  often  get  copies  which  are  blacker  or  weaker 
than  the  original. 

To  copy  oil  paintings  correctly  was  formerly  considered  an  impos- 
sibility. The  colors,  of  course,  cause  much  difficulty ;  a  sun  of  chrome 
yellow  will  appear  as  a  black  spot,  an  ultramarine  blue  sky  will  ap- 
pear white,  not  to  speak  of  other  colors.  The  most  obstinate  color  is 
brown,  and  brown  photographs  are  only  with  great  difficulty  repro- 
duced. Fortunately  the  reflected  light  from  the  colored  surface  acts 
a  little,  but  generally  speaking  a  longer  exposure  will  be  necessary 
with  oil  paintings  than  any  other  pictures  when  we  wish  to  get  detail 
in  the  shadows  and  in  the  inactive  working  colors.  Every  picture 
should  be  examined  most  carefully  after  development.  When  the 
details  in  the  shadows  are  insufficient,  the  time  of  exposure  should 
be  increased  ;  sometimes  this  does  not  insure  success  with  such  colors 


METHODS  OF  OPERATION — FORMULAE.  255 


as  umber  and  dark  green.  Under  these  circumstances  nothing  re- 
mains but  to  replace  the  missing  tones  by  negative  retouch.  Clouds 
and  sky  have  often  to  be  strengthened  by  negative  retouch,  as  they 
will  be  visible  in  the  negative,  but  do  not  offer  sufficient  contrast.  In 
regard  to  the  technicalities  of  negative  retouch,  I  would  refer  to  the 
chapters  on  that  subject  in  the  splendid  work  of  Mr.  Ayres,  entitled 
"  How  to  Paint  Photographs." 

7.  METHODS  OF  OPERATION — FORMULAE. 

The  different  operations  should  be  carried  on  with  the  formulae 
given  above.  For  half  tone  pictures  and  oil  paintings,  I  use  a  strong 
developer ;  for  line  pictures,  I  take  a  feeble  developer. 

For  long  exposures  particularly,  precautionary  measures  are  neces- 
sary. The  repelling  action  of  the  collodion  film  is  very  apt  to  pro- 
duce marbled  stains.  Collodions  from  which  the  bath  runs  off  in 
greasy  lines  are  not  suitable  for  long  exposure.  On  the  other  hand 
there  are  "  moss  stains  "  caused  by  particles  of  dirt  from  the  plate- 
holder  which  become  imbedded  in  the  film,  and  finally  drying  spots, 
by  actual  drying  of  the  silver  solution  on  the  plate,  in  which  case  the 
iodide  of  silver  is  dissolved  by  the  concentrated  bath. 

To  prepare  wet  plates  for  long  exposure,  M.  Carey  Lea  recommends, 
in  the  "  Philadelphia  Photographer,"  the  following : 

1.  Marbled  stains,  which  show  themselves  particularly  in  the  centre 
of  the  plate,  are  best  avoided  by  dipping  the  plate  into  the  silver  bath 
immediately  after  collodionizing. 

2.  Spots,  which  in  spite  of  these  precautions  will  appear,  and  par- 
ticularly at  the  lower  corners,  are  best  avoided, — 

a.  By  the  use  of  two  baths, — an  old  one  for  sensitizing,  and  a  new 
one  for  dipping  the  sensitized  plate  after  it  has  been  taken  from  the 
first  bath.    Take  the  second  bath  only  5  per  cent  strong. 

b.  By  placing  a  thick  strip  of  blotting-paper,  which  is  bent  over 
lengthways  in  such  a  manner  that  one  part  is  about  one-eighth  of  an 
inch  wide,  and  the  other  one  inch  wide ;  the  part  which  is  one-eighth 
of  an  inch  wide  is  placed  under  the  plate,  when  it  is  placed  in  the 
plate-holder,  in  such  a  manner  that  the  plate  rests  on  the  thick  and 
narrow  layer  of  paper.    The  wider  part  is  then  placed  on  the  back. 

c.  By  placing  in  front  of  the  sensitized  plate  a  piece  of  plate-glass 
in  the  holder.  , 

d.  By  placing  damp  cloths  in  the  camera. 

To  keep  the  plate-holder  clean  is  a  matter  of  course.  By  following 
these  directions  an  exposure  of  half  an  hour  or  more  is  possible. 


256 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Covering  the  back  of  the  plate  with  wet  blotting-paper,  and  em- 
ploying a  spongy  collodion,  rich  in  bromine,  is  also  a  remedy  which 
is  to  be  recommended. 

Jabez  Hughes  recommends,  besides  the  above-named  remedies,  the 
employment  of  washed  wet  plates.  The  plates,  after  they  have  been 
sensitized,  are  placed  in  a  large  dish  with  very  pure  distilled  water ; 
they  are  moved  for  about  three  minutes,  the  superfluous  water  is 
allowed  to  drip  off,  and  then  they  are  used.  Before  development 
they  are  returned  to  the  silver  bath,  and  moved  in  it  for  at  least  one 
minute. 

In  the  development,  the  rapid  or  slow  appearance  of  the  picture  is 
a  criterion  whether  the  picture  has  been  over  or  under-exposed.  In- 
tensification is,  particularly  with  line  drawings,  a  point  of  great  im- 
portance. The  plate  must  be  intense  enough  to  offer  a  considerable 
obstruction  to  the  passage  of  light,  otherwise  we  will  get  a  reproduc- 
tion in  which  the  ground  is  gray  instead  of  white. 

Photolithographers  and  photogeographers  require  very  thick  and 
opaque  prints.  For  this  purpose  Osborne  uses  the  following  method 
of  intensifying.  After  the  iron  solution  is  fully  washed  off,  the  plate 
is  immersed  in  a  solution  of  5  parts  of  iodine,  and  10  parts  of  iodide 
of  potassium,  in  100  parts  of  water,  and  remains  in  it  until  it  becomes 
yellow.  The  plate  is  then  thoroughly  washed,  and  a  weakened  solution 
of  sulphuret  of  ammonium  is  poured  over  it,  which  changes  the  color  to 
a  reddish-brown  tinged  with  black.  After  the  plate  is  well  washed  and 
dried,  it  is  varnished  in  the  usual  manner. 

Mr.  M.  Carey  Lea  recommends  the  following: 

Cold  saturated  solution  of  bichromate  of  potash,  .    3  fluid  drachms. 

Hydrochloric  acid,  1  drachm. 

Water,  .........    6  ounces. 

This  solution  is  poured  upon  the  plate  after  it  has  been  intensified 
with  pyrogallic  acid.  The  color  of  the  film  changes  rapidly  into  a 
splendid  lemon-yellow,  and  the  lines  seem  to  become  a  little  clearer. 
When  the  solution  has  been  removed  by  washing,  a  solution  of  sul- 
phate of  ammonia  is  employed,  and  this  changes  the  color  into  a  deep 
chocolate-brown. 

The  only  point  which  requires  particular  attention  is  the  washing 
of  the  plate  after  each  operation,  for  when  this  has  been  neglected  the 
lines  will  run  together,  be  covered  with  precipitates,  and  the  negative 
will  be  spoiled. 

8.  THE  PRINTING. 

Perfect  negatives  will  print  easy,  and  do  not  require  any  artificial 


CRITICISM  OF  THE  RESULT. 


257 


help.  The  printing  is  carried  a  little  into  excess,  that  the  high-lights 
may  show  a  little  color.  In  toning,  the  high-lights  will  become  white. 
Negatives  in  which  some  parts  are  too  thin,  others  too  thick,  have  to 
be  copied  with  a  mask.  The  thin  parts  are  copied  first ;  when  ready 
they  are  covered  with  suitably  cut  pieces  of  pasteboard,  and  the 
dense  parts  are  printed  until  they  reach  the  necessary  amount  of  color. 
The  tone  of  the  picture  should  be  kept  very  black  by  employing  an 
alkaline  or  chloride  of  lime  bath.    See  remarks  thereon. 

9.  CRITICISM  OF  THE  RESULT. 

To  judge  of  the  result,  the  severe  and  critical  comparison  between 
the  copy  and  the  original  is  not  very  difficult  with  drawings  and 
prints,  as  both  are  monochromatic.  It  becomes  more  so  with  oil 
paintings.  With  these  the  effect  of  color  has  to  be  reproduced  by  the 
mere  graduation  of  tone  between  light  aud  dark.  We  have  to  ob- 
serve at  the  start  that  in  photography  the  cold  colors  (blue)  are  re- 
produced too  light,  while  the  warm  colors  (yellow  and  red)  are  ren- 
dered too  dark.  This  contrast  has  to  be  equalized  if  the  picture  is  to 
be  true.  We  have,  so  to  say,  to  analyze  the  colored  original.  We 
have  to  ignore  the  color,  and  have  to  observe  what  should  be  light, 
half  shadow,  and  dark  ;  what  should  be  prominent  and  what  not. 

When,  in  a  photograph,  the  proper  gradation  between  light  and 
shade  is  wanting,  the  figures  will  not  separate ;  the  picture,  in  short, 
lacks  character,  and  is  worthless. 

Whoever  wishes  to  photograph  works  of  art  correctly  must  be  an 
artist  himself,  or  else  submit  to  the  superior  judgment  of  an  artist. 

There  are  hundreds  of  reproductions  of  oil  paintings  in  the  market 
which  show  light  where  the  original  is  dark,  and  vice  versa;  or  where 
the  several  figures  which  in  the  original  are  properly  separated  by 
contrast  of  color,  appear  in  the  copy  as  an  undefined  mass ;  or  large 
surfaces  show  nothing  but  shadow  where  the  original  is  full  of  deli- 
cate detail.  All  these  several  points  have  to  be  observed,  and  only 
by  exercising  a  sound  criticism  can  a  satisfactory  result  be  secured. 
Oil  paintings,  which  have  become  dark  by  age,  and  in  which  the  eye 
does  not  recognize  any  details,  of  course  cause  more  difficulty  than 
new  ones. 

Eeproductive  photography  is  a  branch  which  stands  on  the  border 
between  the  purely  mechanical  and  artistical  activity  of  the  photog- 
rapher. So  far  as  it  is  based  on  artistic  principles,  it  belongs  to  the 
chapter  on  Photographic  ^Esthetics ;  practical  considerations  induced 
me,  however,  to  treat  of  it  in  the  purely  technical  part  of  my  book. 

17 


258 


THE  PRACTICE  OF  PHOTOGRAPHY. 


SECTION  II. 
THE  "LICHTPAUS"  PROCESS. 

By  "Lichtpausen"  is  understood  the  direct  printing  of  a  sketch  by 
the  aid  of  light,  without  application  of  the  negative  process.  This  is 
one  of  the  simplest  photographic  processes  in  existence,  because  it  only 
requires  the  operation  of  the  positive  process  (see  above),  to  which  it 
has  some  similarity.  One  thing  is  dispensed  with,  namely,  toning, 
which  is  of  little  consequence,  it  being  immaterial  whether  the  techni- 
cal drawing  has  a  brown  tone  or  not.  This  process  has  the  one  advan- 
tage above  the  negative  process :  it  can  furnish  prints  in  original  size 
to  dimensions,  which,  in  the  negative  process,  cannot  very  easily  be 
obtained.  The  process,  since  the  sensitized  paper  can  be  bought  al- 
ready prepared  at  the  dealers,*  is  so  simple  that  persons  not  acquainted 
with  photography  can  practice  it  with  the  greatest  ease.  This  ac- 
counts for  its  universal  application  in  large  machine  shops,  bureaus  of 
architecture,  etc.,  etc.  In  this  process,  both  negative  and  positive  are 
made,  but  both  on  paper  without  development.  The  negative  is 
formed  by  exposing  the  sensitized  paper  under  a  drawing  or  sketch ; 
the  black  lines  keeping  off  the  light  will  be  produced  white,  and  the 
whites  of  the  original  black.  It  is  best  to  use  plain  paper;  albumen 
paper  is  apt  to  curl  or  roll,  and  break.  The  sketch  to  be  printed  must 
shine  through,  and  have  some  vigor  in  its  lines.  It  is,  however, 
totally  superfluous  to  make  the  sketch  transparent  with  paraffin  or 
varnish ;  under  certain  circumstances  possibly  it  might  be  spoiled. 
Sketches  will  print  without  this,  of  course  a  little  slower  the  thicker 
they  are.  Even  originals  on  copperplate  printing  paper  can  be 
printed ;  of  course,  the  paper  must  not  be  too  yellow.  Colored  sketches 
will  print  as  good  as  those  not  colored,  except  aniline  blue.  The 
more  opaque  the  lines  of  the  original  are,  the  more  brilliant  will  be 
the  print.  It  is  to  be  recommended  to  sketchers  to  add  vermilion  or 
Vandyke  brown  to  their  india-ink  in  sketching,  to  make  them  chemi- 
cally more  opaque.  Conditions  to  attain  a  sharp  print  are  that  the 
original  drawing  and  the  paper  should  be  in  close  contact.  To  effect 
this,  they  are  pressed  together  in  the  printing-frame  as  usual,  the 
sketch  laid  in  the  frame,  picture-side  up,  the  sensitive  paper  on  top. 
If  the  wrong  side  of  the  sketch  is  laid  up,  they  are  separated  the 
thickness  of  the  paper,  and  it  will  be  impossible  to  obtain  a  sharp 


*  It  is  manufactured  by  Herr  Talbot,  No.  11  Karl  Street,  Berlin. 


THE  "LICHTPAUS"  PROCESS. 


259 


print,  unless  the  paper  which  holds  the  sketch  is  very  thin.  In  re- 
gard to  contact  a  good  pressure  is  important.  Talbot  has  introduced 
sheep-wool  bolsters,  which  are  better  than  the  paper  pads,  which  are 
easily  rumpled  and  then  press  unevenly.  Several  thicknesses  of  cloth 
can  be  used.  The  pressing  pads  are  placed  on  the  paper,  the  frame 
closed,  and  inspected  from  the  front  or  glass  side ;  if  any  folds  or 
pleats  have  formed  at  all  (best  done  in  a  light  falling  sideways), 
they  are  removed  by  pieces  of  cardboard  placed  back  of  the  paper. 
Drawings  the  size  of  45  centimetres  are  easily  pressed  flat  in  this  man- 
ner; larger  ones  are  more  troublesome.  To  keep  these  flat,  it  is  best 
to  stretch  them  on  the  plate  in  the  printing-frame.  Wet  the  back  of 
the  sketch  with  a  sponge,  and  paste  it  on  the  glass.  In  drying  it 
will  be  perfectly  flat,  and  print  very  well.  The  sketch  can  after- 
wards be  removed  by  moistening  with  hot  water.  Care  must  be  taken 
that  the  original  is  fully  dry  before  laying  on  the  sensitive  paper,  as 
the  silver  is  apt  to  adhere  to  the  paper  and  make  spots.  Spots  of  this 
kind  can  be  removed  with  chloride  of  mercury ;  it  is  better,  however, 
to  avoid  them.  In  regard  to  the  printing,  it  is  the  same  as  print- 
ing from  a  negative.  The  prints  must  be  examined  occasionally,  to 
watch  the  progress  of  the  process,  and  printed  deeper  than  the  pic- 
ture is  intended,  as  it  will  come  up  lighter  in  the  fixing  bath.  It 
is  better  to  print  too  dark  than  too  light,  as  the  dark  ones  can  be 
bleached,  too  light  ones  cannot  be  cured.  Prints  on  Talbot's  paper 
can  be  kept  for  weeks,  without  fixing,  in  the  dark.  The  toning  is  dis- 
pensed with.  In  behalf  of  fixing,  the  prints  are  washed  once  in  water. 
Asphalted  wooden  dishes,  as  furnished  by  Talbot,  will  answer,  and 
must  be  kept  perfectly  clean.  Care  must  be  taken  to  have  clean 
fingers,  and  avoid  hypo  stains.  The  prints  are  saturated,  and  left  to 
soak  in  water  about  three  minutes ;  afterwards  dip  in  the  fixing  bath. 

Hypo,     .......    1  pound. 

Water,    .......    5  pounds. 

Ammonia,      ......    £  pound. 

The  latter  neutralizes  any  acid  often  contained  in  the  paper.  Papers 
which  are  dipped  in  without  washing,  will  fade  from  the  influence  of 
the  acid.  The  first  wash-water  is  saved,  and  the  silver  contained 
precipitated  with  table-salt  (see  above).  By  taking  large  sheets  out 
of  the  water,  care  is  necessary  to  avoid  tearing.  In  immersing  in  the 
fixing  solution  the  prints  change  from  a  violet  to  a  brown  color.  The 
second  print  is  placed  into  the  fixing  solution  when  the  change  in 
the  first  has.  completely  taken  place.  Remaining  in  the  fixing  so- 
lution ten  minutes,  they  are  placed  in  a  dish  of  clean  water  for  three 


260 


THE  PRACTICE  OF  PHOTOGRAPHY. 


minutes,  and  from  this  into  another  one.  This  is  repeated  eight  times. 
Small  prints  are  hung  up  with  clothes-pins  to  dry;  large  ones  are 
dried  on  blotting-paper.  The  washing  of  the  latter  is  best  accom- 
plished in  one  dish,  which  has  an  opening  in  the  bottom,  with  a  gum 
hose  attached.  Let  the  water  off  with  it,  and  change  eight  times. 
In  washing  and  fixing  the  prints,  the  tilting  to  and  fro  of  the  dish 
must  not  be  neglected,  so  as  to  further  the  flowing  of  the  solution. 
If  the  solution  do  not  moisten  and  penetrate  the  prints  thoroughly, 
ordinary  fixing  and  washing  are  impossible.  Insufficient  washing  turns 
the  prints  yellow.  To  ascertain  if  they  are  sufficiently  washed,  apply 
the  iodine  test.  Too  dark  prints  are  bleached  by  placing  them  in  a 
solution  of  1  part  of  cyanide  of  potassium  to  500  parts  of  water,  and 
tilting  the  dish  to  and  fro  diligently.  The  bleaching  occurs  from  the 
silver  dissolving,  the  outlines  consisting  of  brown  metallic  silver. 
With  the  negative  so  produced,  the  position  of  which  is  reversed  to 
the  original,  a  positive  can  be  produced  in  the  manner  described, 
which  fully  resembles  the  original.  Very  large  drawings  are  copied 
in  pieces  or  parts,  by  folding  them  so  that  one  part  covers  the  back  of 
the  paper.  With  small  pieces  of  paper,  large  drawings  can  also  be 
printed  by  placing  them  so  that  the  edges  overlap  each  other.  Any 
part  of  the  drawing  not  desired  can  be  touched  out  with  india-ink. 
White  spots  in  the  negative  are  touched  out  in  the  same  manner. 


SECTION  III. 

PHOTOGRAPHING  OF  MODELS,  ORNAMENTS,  STATUES,  WORKS  OF 
ART,  MACHINERY,  ETC. 

1.  PREPARATION  OF  THE  OBJECT,  AND  ARRANGEMENT. 

It  is  difficult  to  find  general  rules  for  the  parti-colored  medley  of 
objects  which  have  been  arranged  in  this  section,  as  these  have  to  be 
modified  by  every  especial  case,  and  I  will  only  try  to  develop  those 
principles  which  one  dare  not  neglect  in  taking  the  picture  of  such 
objects  as  are  named  above. 

The  rules  which  are  laid  down  for  reproductions  also  hold  good 
here.  Everything  which  does  not  belong  to  the  object  proper  should 
be  removed,  and  no  pains  should  be  spared  to  make  the  object  as  ele- 
gant as  possible  before  proceeding  to  the  taking  of  the  picture. 

The  objects  which  come  under  this  head  are  either  easily  removed 
(can  be  transported  to  the  atelier)  or  not.  The  latter  have  to  be 
taken  at  the  spot  where  they  are  located,  with  all  the  accidental  sur- 


PREPARATION  OF  THE  OBJECT,  AND  ARRANGEMENT.  261 


roimdings — landscape  background,  spectators,  etc.;  sometimes  with 
an  unsuitable  or  even  impossible  illumination,  in  dark  cellars,  etc. 

Objects  which  can  be  brought  to  the  atelier  are  best  placed  in  front 
of  a  monotonous  or  plain  background.  According  to  the  nature 
of  the  object  different  shades  are  necessary.  As  a  general  rule,  we 
may  state  that  the  object  must  contrast  with  the  background.  They  must 
not  be  equally  light  or  dark.  It  will  be  observed  that  the  background 
becomes  darker  by  moving  it  away  from  the  object.  This  enables  us 
to  make  a  completely  black  background  on  the  picture  with  a  screen 
which  naturally  is  only  gray.  A  background  which  is  too  dark  can 
be  lighted  up  by  a  suitable  illumination.  As  a  basis  we  should  select 
a  dark  table  or  a  support  of  a  sombre  color.  All  other  things  should 
be  removed.  A  vertical  position  is  almost  a  matter  of  course.  The 
selection  of  the  position  of  the  camera  is  of  much  importance.  The 
camera  has  to  be  placed  at  the  spot  where  an  expert,  but  not  a  pho- 
tographer, would  place  himself  to  get  a  full  view  of  the  whole  object. 
The  direction  in  which  the  camera  is  placed  should  correspond  with 
the  direction  of  the  eye  of  such  an  observer.  It  is  therefore  necessary 
that  the  photographer  should  perfectly  know  his  subject  if  he  wants 
to  select  the  proper  standpoint.  Of  what  use  is  the  most  brilliant 
picture  of  a  piece  of  machinery  when  the  main  things  are  hidden  by 
secondary  matters.  Sometimes  this  may  depend  on  a  single  wheel  or 
a  single  screw.  It  is  the  same  with  objects  of  art.  The  photographer 
has  to  study  his  subject,  exactly  as  the  actor  has  to  study  the  charac- 
ter which  he  is  to  represent. 

Whoever  wishes  to  take  pictures  of  plastic  figures,  must  understand 
the  plastic  art;  he  must  be  possessed  of  artistic  judgment,  or  he  will 
commit  gross  errors. 

The  same  holds  good  for  technical  objects,  as  stores,  machinery, 
tools,  and  reliefs.  Any  one,  not  being  an  expert  in  these  matters, 
should  at  least  consult  some  one  who  understands  it  thoroughly.  In 
taking  works  of  the  plastic  art,  he  should  consult  the  sculptor ;  in 
taking  technical  objects,  he  should  consult  a  mechanic,  who  will  point 
out  to  him  which  parts  are  essential  and  which  are  not.  The  en- 
graver has  to  do  the  same  when  he  desires  to  make  an  engraving  of 
an  intricate  piece  of  machinery. 

The  advantages  of  photographic  pictures  of  technical  objects  have 
often  been  estimated  as  being  of  very  little  value.  The  reason  is  that 
the  pictures  were  made  by  photographers  who  did  not  understand 
their  subject.  Not  photography  but  its  disciples  are  to  be  blamed. 
My  space  does  not  permit  me  to  give  detailed  instructions  to  every 
one  who  wishes  to  photograph  statues,  or  machinery,  or  architectural 


262 


THE  PRACTICE  OF  PHOTOGRAPHY. 


objects.  Fortunately  our  literature  is  not  deficient  in  such  works, 
and  it  is  the  duty  of  every  one  to  instruct  himself  in  these  matters.* 
The  cultivation  of  these  specialties  is  the  reason  why  we  have  nowa- 
days portrait  photographers,  landscape  photographers,  and  architec- 
tural and  technical  photographers.  The  practical  manipulations  are 
nearly  always  the  same ;  but  the  particular  success  in  any  one  of 
these  branches  is  based  on  particular  knowledge  of  the  subject-matter. 
It  is  not  unusual  to  find  that  a  skilful  portrait  photographer  will 
make  a  poor  hand  at  landscape  photography,  and  a  good  worker  at 
reproductions  will  fail  completely  in  portraiture. 

When  the  proper  side  from  which  the  picture  should  be  taken  has 
been  found,  the  distance  is  the  next  important  subject.  When  the 
camera  has  been  placed  too  near,  perspective  exaggerations  are  apt  to 
take  place ;  even  with  the  best  of  lenses  the  nearer  parts  appear  too 
large.  When  the  camera  is  removed  too  far,  the  relief  is  apt  to  seem 
too  flat.  The  photographer  will  be  very  apt  to  make  the  former  mis- 
take from  want  of  distance,  and  (when  working  in  a  contracted  space) 
he  often  has  no  other  choice.  Vertical  position  of  the  camera  is  gen- 
erally necessary,  particularly  when  taking  technical  objects  (models, 
etc.).  Under  certain  circumstances,  however,  an  inclined  position  of 
the  camera  has  to  be  selected.  Take,  for  instance,  a  statue  on  a  high 
pedestal,  which  we  are  accustomed  to  see  from  below,  and  which  has 
been  constructed  by  the  artist  with  reference  to  this  position.  It 
would  be  absolutely  faulty  if  we  would  copy  such  a  statue  in  the 
atelier  on  a  level  with  the  camera.  On  the  contrary,  it  should  be 
placed  high,  and  the  apparatus  should  point  upwards ;  by  doing  so 
we  will  only  conform  to  the  natural  conditions  for  which  the  statue 
has  been  constructed.  We  know  works  of  art,  as,  for  instance,  the 
George's  Head,  by  Kiss,  which,  when  seen  from  a  level,  look  indif- 
ferent, and  only  make  a  startling  impression  when  viewed  from  below. 

We  often  sin  against  these  principles.  Portrait  photographers,  who 
are  accustomed  to  incline  their  cameras  on  the  sitter,  too  frequently 
apply  this  position  for  all  other  objects.  I  would  here  call  the  atten- 
tion of  the  photographer  to  what  will  be  said  in  the  article  on  Per- 
spective. 

2.  ILLUMINATION  AND  EXPOSURE. 

The  selection  of  the  proper  illumination  is  as  important  as  the  selec- 
tion of  the  proper  standpoint.  Artistic  objects  require  analogous  con- 
siderations to  portraits  (see  ^Esthetics)  ;  technical  objects  must  appear 

*  We  would  recommend  Liibke's  History  of  Architecture,  also  Liibke's 
History  of  Plastics. 


ILLUMINATION  AND  EXPOSURE. 


263 


distinct  in  all  particulars ;  dark  shadows,  which  are  apt  to  obliterate 
some  details  completely,  should  be  avoided.  The  light  of  a  high 
atelier,  which  pours  in  uniformly,  is  preferable.  Objects  which  have 
to  be  taken  in  a  given  locality  can  of  course  not  be  brought  into 
a  suitable  illumination.  We  have  to  wait  for  the  suitable  moment, 
and  very  often  we  have  to  assist  with  mirrors,  magnesium  light,  or 
other  artificial  means. 

By  the  aid  of  a  mirror  sunlight  is  thrown  on  the  object  (it  is  best 
to  follow  the  direction  of  the  camera)  ;  and  by  slightly  moving  the 
mirror  the  light  is  passed  to  and  fro  over  the  whole  object.  Objects 
which  are  much  hidden  can  often  only  be  reached  by  two  mirrors,  and 
the  light  proceeding  from  the  first  has  to  be  caught  by  a  second  one, 
and  is  from  it  reflected  on  the  object.  Of  course,  with  such  a  process, 
much  light  is  lost.  The  time  of  exposure,  for  such  an  illumination, 
in  July,  with  a  Steinheil  lens,  and  third  largest  stop,  is  with  a  single 
mirror,  about  six  minutes ;  with  two  mirrors,  from  nine  to  twelve 
minutes  ;  the  object  being  dark. 

The  following  principles  of  illumination  and  perspective  refer  to  all 
objects.  The  specially  noted  lifeless  models  are  very  different  in  their 
character ;  sometimes  purely  artistic,  as  plaster  models,  marble  figures, 
etc. ;  sometimes  purely  technical,  as  models  of  machinery ;  sometimes 
of  a  dark  color  (cast  iron)  ;  sometimes  white  (plaster  of  Paris). 

How  extremely  different  the  treatment  of  such  bodies  must  be  is 
self-evident.  A  white  figure  requires  a  dark  background,  a  dark  one 
(bronze  or  iron)  requires  a  light  one  ;  the  former  a  short  exposure,  the 
latter  a  long  one.  Remember,  too,  that  high -lights  often  make  their 
appearance  on  metallic  objects,  and  require  to  be  modified  by  suitable 
illumination,  or  by  dusting  the  respective  parts  with  gray  chalk.  Still 
more  annoying  are  colors ;  very  often  we  have  to  distinguish  between 
red  cast  (copper)  and  bronze  ;  both  act  photographically  alike.  We 
must  resort  to  negative  retouch  for  separating  parts  which  should  be 
kept  apart,  but  which  will  run  together  on  account  of  color. 

For  taking  buildings  in  the  open  air,  a  light  falling  from  the  front 
at  an  angle  of  45°  is  the  most  advantageous.  The  exposure  should 
be  continued  until  all  the  details  in  the  shadows  appear. 

3.  LENSES. 

In  the  selection  of  lenses  freedom  from  distortion  should  be  looked 
for.  For  objects  that  give  out  very  little  light,  portrait  lenses  should 
be  used  ;  where  correctness  of  drawing  is  the  main  object  (machinery), 
doublets  or  aplanatic  lenses  are  the  best ;  with  a  large  angle  and  short 
distance,  the  pantoscope  is  preferable.    I  repeat,  that  acquaintance 


264 


THE  PRACTICE  OF  PHOTOGRAPHY. 


with  the  object  is  necessary  for  the  proper  selection  of  the  lens.  The 
same  refers  to  stops. 

It  is  advantageous  to  place  over  a  piece  of  machinery  white  gradu- 
ated marks  lengthways,  perpendicular,  and  horizontal ;  they  should 
be  included  in  the  photograph,  as  with  a  knowledge  of  the  perspec- 
tive the  dimensions  can  be  reduced  from  them. 

The  negative  and  positive  processes  are  practiced  according  to  the 
rules  given  in  previous  chapters.  A  strong  developer,  however,  should 
be  used. 

SECTION  IV. 

STEREOSCOPIC  PICTURES. 

For  taking  stereoscopic  pictures,  it  is  necessary  to  have  two  views 
of  the  same  subject,  one  a  little  from  the  right,  and  the  other  a  little 
from  the  left  side.  These  pictures  (see  Part  I)  can  be  made,  first, 
in  a  very  simple  manner,  with  an  ordinary  camera  set  on  a  stand, 
with  a  wide  board.  The  board  B  (Fig.  78)  is  perpendicular  to  the 
line  of  communication  of  the  viewer  with  the  object.  Take  either  a 
camera  with  a  movable  holder,  in  which  two  pictures  are  made  one 
after  the  other,  or  one  with  a  movable  object-lens  and  internal  divi- 
sions (K,  Fig.  78).    Such  a  camera  is  first  placed  on  the  right  side  of 


Fig.  78. 


the  board  towards  the  groove.  The  right-hand  picture  is  taken  on 
the  left  side  of  the  plate,  looking  at  it  from  the  rear.  Next  the  camera 
is  placed  on  the  other  side  from  B,  and  we  take  the  left  side  of  the 
object  on  the  right  side  of  the  plate.  That  the  camera  retains  exactly 
the  same  distance  from  the  object  is  very  necessary,  and  the  board 
should  be  placed  very  firm.  The  binding-screw,  K,  of  the  camera 
passes  through  holes  bored  in  the  board,  or  runs  in  a  groove,  in  order 
that  the  position  of  the  camera  may  be  fixed  at  any  time. 

The  length  of  the  board  for  distances  of  about  twenty-five  feet  is 


STEREOSCOPIC  PICTURES. 


265 


about  a  foot.  With  nearer  objects  it  is  less.  With  great  distances 
we  take  four  to  five  feet  and  even  more.  When  too  much  length  has 
been  given  to  the  board  for  near  objects,  they  will  appear  unnaturally 
solid,  while  the  reverse  produces  pictures  that  are  flat. 

This  method  will  not  do  for  moving  or  living  objects,  as  these  are 
apt  to  change  their  position,  and  the  second  picture,  even  if  it  should 
be  sharp,  would  not  be  in  its  proper  place,  and  would  appear  distorted 
in  the  stereoscope. 

Even  in  landscape  photography  this  method  has  great  drawbacks, 
as  the  illumination  will  sometimes  change  between  the  taking  of  the 
first  and  second  picture. 

The  second  method  is  with  a  camera  with  two  tubes.  With  it 
both  pictures  are  taken  at  the  same  time.  A  change  in  position  or 
illumination  has  no  influence  here,  as  both  pictures  are  taken  simul- 
taneously ;  but  as  the  tubes  cannot  be  very  far  removed  from  one 
another  the  right  and  left  view  differ  very  little,  and  the  distances  do 
not  appear  very  solid. 

In  Germany  we  use  the  German  and  English  boxes  for  this  work. 

A  very  practical  camera  for  stereoscopic  work  is  the  one  called  the 
"  Philadelphia  Box,"  made  by  the  American  Optical  Company,  New 
York,  and  one  of  which  was  presented  me  by  the  Scovill  Manufactur- 
ing Company. 

It  consists  of  a  rigid  front  part  (Fig.  79),  and  the  back  part,  D, 
which  moves  back  and 
forth  on  the  platform.  It 
also  has  fronts  for  the  tubes. 
The  focussing  is  done  by 
moving  the  back  part  over 
the  brass  guides,  G  G,  and 
securing  the  exact  focus  by 
using  the  focussing  screw, 
F.  The  opening  and  shut- 
ting of  the  tubes  is  done 
with  a  cloth,  the  common 
method,  I  find,  in  America. 
Some  of  the  foreign  boxes 
have  an  instantaneous  front, 
which  moves  around  an 
axis,  and  which  can  be 
rapidly  raised  and  depressed 
by  turning  a  knob.  The  exposure  can,  of  course,  be  lengthened  at 
pleasure.    The  whole  arrangement  fits  only  loosely  on  the  objective, 


266 


THE  PRACTICE  OF  PHOTOGRAPHY. 


and  is  easily  removed.  The  front  board  with  the  stereoscopic  lenses 
it  also  easily  detached  and  replaced  by  another  board  carrying  a  single 
lens.  This  same  arrangement  may  be  applied  to  the  American  boxes 
when  necessary. 

The  inside  of  the  camera  is  divided  by  a  movable  piece  or  dia- 
phragm A  (Fig.  79),  which  moves  in  a  groove,  and  which  doubles  on 
itself  in  shortening  the  camera,  and  lengthens  when  the  camera  is 
pulled  out,  so  as  always  to  completely  divide  the  camera  into  two 
parts. 

Fig.  79  represents  the  box  as  it  is  used  for  ordinary  stereoscopic 
wTork.  The  platform  is  hinged  so  that  it  may  fold  up  compactly ;  the 
bellows  is  rubber ;  the  swing-back,  which  is  indispensable  for  landscape 
work,  is  attached  ;  the  front  raises  and  lowers,  and  the  holder  is  made 
to  fit  on  pins,  which  is  far  preferable  to  a  holder  which  slides.  The 
ground-glass  is  hinged  fast.  Fig.  80  represents  the  box  turned  over 
on  its  side,  for  the  purpose  of  making  an  upright  single  view  with  one 
tube,  as  recommended  by  Wilson.  The  partition  or  diaphragm  A 
(Fig.  79)  is  removed,  so  the  plate  is  not  obstructed  or  divided.  C  is 
a  clasp  which  holds  the  holder  in  place  when  the  exposure  is  being 
made,  and  at  E  is  a  clasp  and  screw,  which  keep  the  holder  at  a 
proper  swing  or  angle  when  it  is  necessary  to  use  the  swing-back. 
G  G  are  the  metal  guides ;  D  D  screws  which  bind  the  platform  to 
the  box  when  in  use ;  F  the  focussing  screw. 

The  plate-holders  have  corners  of  solid  glass  on  which  the  sensi- 
tive plate  rests.  Drawings 
of  them  will  be  found  on 
another  page. 

The  lenses  which  may  be 
used  with  this  camera  have 
an  opening  of  1\  and  1-J 
inches,  and  from  to  6 
inches  length  of  focus  (cal- 
culated from  the  back  lens). 
They  should  be  provided 
with  stops ;  the  sizes  so  ar- 
ranged that  with  each  one 
twice  as  long  a  time  of  ex- 
posure is  required  as  with 
the  next  larger  one.  But 
stops  are  only  necessary  for 
very  near  objects.  Long  distances  we  can  work  with  the  full  opening. 
The  above-described  screen  for  taking  instantaneous  pictures  offers 


STEREOSCOPIC  PICTURES. 


267 


some  difficulties.  Great  care  has  to  be  observed  that  in  moving  it 
neither  the  tubes  nor  the  camera  are  shaken.  The  taking  of  instan- 
taneous pictures  requires  steadiness  and  skill. 

Lately  another  instantaneous  shutter  has  been  invented,  which  is 
warmly  recommended  by  Remele.*  It  consists  of  a  wooden  box  which 
is  placed  over  the  tubes.  In  the  box  is  a  curtain  which,  by  being 
pulled  over  the  tubes,  shuts  out  the  light.  This  can  be  done  rapidly 
or  slowly,  as  circumstances  may  require.  This  arrangement  admits 
also  of  giving  different  lengths  of  exposure  to  different  parts  of  the  same 
picture ;  for  instance,  the  sky  and  distant  parts  of  the  landscape  may 
receive  a  very  short  exposure,  and  the  foreground  considerably  more 
without  interrupting  the  pulling  of  the  curtain-string  a  moment.  With 
many  landscapes,  for  the  longer  exposure  of  the  foreground,  and  the 
shorter  time  given  to  the  sky,  it  is  of  great  importance,  particularly 
with  distant  views.  With  a  lid  the  illumination  would  have  to  be  an 
average  one,  or  the  middle  parts  of  the  picture  would  be  correctly 
timed,  while  the  background  and  sky  would  be  completely  over-ex- 
posed, and  the  foreground,  which  generally  shows  some  foliage,  would 
be  wanting  in  detail.  By  giving  a  short  exposure  to  the  sky  the  most 
beautiful  cloud  effects  can  be  obtained.  The  pictures  which  are  made 
with  the  above  curtain  arrangement  show  a  beautiful  harmony,  and 
many  faults  in  the  illumination  which  we  see  on  other  pictures  are 
entirely  avoided. 

Rouch  has  constructed  a  screen  for  instantaneous  pictures  which 
has  two  shutters  instead  of  one,  as  in  the  other  arrangement.  These 
shutters  turn  around  a  small  axis,  which  is  provided  with  teeth  which 
connect  them  with  a  swivel  on  the  centre  of  the  box  at  each  side.  It 
is  evident  that  when  the  upper  shutter  is  turned  with  the  knob  the 
lower  shutter  will  have  to  turn  also,  and  that  both  must  move  in  the 
same  direction.  When  the  arrangement  is  closed  by  the  upper  shutter 
then  both  shutters  will  stand  vertical  above  their  axis  ;  when  the  knob 
is  turned  backwards  the  lower  shutter  will  be  depressed,  and  the  tubes 
will  be  opened,  but  will  be  closed  again  immediately  when  the  upper 
shutter  places  itself  in  front  of  them. 

The  movements  of  the  apparatus  are  simpler  than  those  of  the 
Dallmeyer  instantaneous  shutter,  but  it  requires  skill  and  steadiness 
to  operate  them. 

Braun,  in  Dornach,  manages  the  opening  and  shutting  of  the  tubes 
in  a  peculiar  manner.    He  closes  both  tubes  with  a  black  cloth  which 


*  Kemele's  Handbook  of  Landscape  Photography. 


268 


THE  PRACTICE  OF  PHOTOGRAPHY. 


he  holds  flat  in  the  hand ;  he  removes  it  rapidly,  and  replaces  it  as 
rapidly  again.    This  movement,  however,  requires  much  practice. 

For  portraiture  the  lenses  should  be  2J  inches  distant  (the  distance 
of  the  eyes).  For  landscapes  a  greater  distance  is  desirable.  English 
mechanics  have  placed  the  tubes  on  boards  which  can  be  moved  in  a  hori- 
zontal direction,  which  admit  of  their  being  placed  a  little  closer  together 
or  a  little  further  apart.  Of  course  the  shutter  arrangement  is  not 
always  applicable  to  this  arrangement. 

All  kinds  of  lenses  are  used  for  taking  stereoscopic  pictures : 

1.  Portrait  lenses,  where  a  quick -working  lens  is  desired  (for  mov- 
ing objects,  portraits,  instantaneous  views,  etc.). 

2.  Doublets,  aplanatic  lenses,  correct  wide-angled  lenses,  where  cor- 
rect drawing  and  a  large  field  of  view  is  desired.  Vertical  position 
of  the  camera  is  necessary.  The  tube  must  have  an  arrangement  by 
which  it  can  be  raised  and  lowered,  in  order  that  the  picture  on  the 
ground-glass  may  be  centred.  By  raising  the  tubes  the  sky  will  be- 
come larger,  by  lowering  them  the  foreground  will  increase  in  size. 

3.  Landscape  lenses,  where  a  little  distortion  does  not  amount  to 
much. 

The  methods  of  operation  are  in  no  way  different  from  the  ordinary 
methods.  Plates  should  be  selected  which  are  a  little  larger  than  the 
picture  is  to  be.  In  this  way  spots  at  the  corners  are  easier  avoided. 
It  should  also  be  observed  that  plates  taken  in  the  double  camera 
show,  when  seen  from  the  glass  side  in  an  upright  position,  the  right 
side  to  the  left,  and  the  left  side  to  the  right.  They  must,  therefore, 
be  cut  apart,  and  their  positions  reversed. 

When  this  is  done  at  once  with  the  plates  it  will  afterwards  no 
longer  be  necessary  to  do  it  with  the  prints.  When,  however,  the 
pictures  are  farther  apart  than  inches,  which  is  the  ordinary  stereo- 
scopic distance,  it  is  better  to  print  them  together,  and  to  reverse 
them  when  ready  for  mounting. 

The  difference  in  the  amount  of  light  in  two  different  lenses  is  often 
a  great  drawback,  as  they  will  yield  pictures  of  different  intensities, 
and  one  is  compelled  in  such  cases  to  stop  the  one  lens  until  it  corre- 
sponds in  intensity  with  the  other. 

It  happens  more  frequently  that  the  thin  end  (the  end  first  poured 
upon)  of  the  stereo  plate,  is  not  as  sensitive  as  the  thick  end  (run- 
ning-off  end).  Through  this  the  pictures  are  constantly  uneven.  This 
can  only  be  avoided,  in  coating  plates,  by  pouring  on  a  goodly  quan- 
tity of  collodion,  letting  it  flow  backward  over  the  plate  before  leaving 
it  run  off  the  plate.  For  the  above  reasons,  plates  larger  than  the 
picture  should  be  used. 


INSTANTANEOUS  PICTURES. 


269 


INSTANTANEOUS  PICTURES. 

There  was  a  time  when  instantaneous  pictures  were  the  theme  of 
every-day  conversation,  and  when  they  gave  rise  to  the  most  wonder- 
ful illusions.  The  representative  Faucher  made,  in  the  Prussian 
Chamber  of  Deputies  on  July  1,  1869,  the  following  remarks : 

"We  have  now  instantaneous  pictures.  By  this  process  portraits 
can  be  stolen,  and  perhaps  the  most  extraordinary  precautionary 
measures  will  be  necessary  to  guard  against  such  a  theft ;  perhaps  it 
will  finally  be  necessary  to  wear  a  mask." 

These  rumors  probably  owed  their  origin  to  the  splendid  stereos  of 
Braun  and  Ferrier  with  walking  figures,  carriages  in  motion,  horses, 
etc.  The  public  as  well  as  photographers  considered  it  possible  to 
produce  instantaneous  pictures  in  the  atelier.  Even  photographers 
advertised  themselves  in  the  papers  as  "instantaneous  photographers," 
and  very  often  we  heard  in  those  days  the  exclamation,  "Yes,  if  I 
had  his  collodion,"  as  if  everything  depended  on  the  collodion. 

I  have  mentioned  in  another  place  that  the  production  of  instanta- 
neous pictures  is  only  possible  under  certain  favorable  conditions:  (1) 
a  good  collodion ;  (2)  bright  light ;  (3)  a  lens  that  gives  a  great  deal 
of  light ;  (4)  a  new  and  pure  silver  bath ;  (5)  a  strong  developer. 

But  even  to  this  day  we  hear  of  instantaneous  portraits.  "  There 
must  be  something  in  it,"  say  a  great  many ;  and  here  we  must  refer 
to  an  episode  in  the  Berlin  Photographic  Society,  when  Mr.  Ahrens 
put  the  question,  "What  is  a  photographic  moment?"  The  answer 
was,  "Three  seconds." 

Of  course,  instantaneous  pictures  have  been  taken  in  much  shorter 
time  than  this,  but  what  are  they  like  ? 

In  a  good  portrait  we  want  modulation.  This  can  only  be  obtained 
by  a  skilful  direction  of  the  light,  which  must  not  pour  in  from  all 
sides,  but  must  be  excluded  here  and  there. 

But  this  diminishes  the  quantity  of  light,  and  does  not  suffice  for 
condition  No.  2. 

On  the  other  hand,  clearness  in  the  shadows  is  demanded ;  this  can 
only  be  obtained  by  long  exposure. 

Hence,  the  real  instantaneous  pictures,  taking,  for  instance,  a  space 
of  time  not  more  than  one-tenth  of  a  second,  are  reduced  to  landscapes 
with  their  accessories  in  clear,  sunny  weather.  And  for  this  purpose 
we  recommend — 

1.  Collodion  made  by  any  reputable  party,  or,  when  the  photogra- 
pher wishes  to  prepare  it  himself,  make  it  according  to  formula  given.* 


*  When  the  following  conditions  are  observed,  a  less  sensitive  collodion 
will  suffice. 


270 


THE  PRACTICE  OF  PHOTOGRAPHY. 


2.  Apparatus — a  double  objective  of  short  focus  giving  much  light, 
with  an  instantaneous  shutter. 

3.  Bath,  1  :  10,  freshly  made  of  crystallized  silver  and  one-quarter 
per  cent,  of  the  salt  of  iodide  of  potassium. 

4.  Developer  after  Eemele :  viz.,  5  iron,  1J  glacial  acetic  acid, 
100  water  (alcohol  is  not  always  necessary).  Some  "instantaneous 
collodions "  of  commerce  are  apt  to  work  foggy  with  this  developer. 
In  that  case  more  acid  should  be  added. 

5.  Intensifying  and  fixing  as  usual.  The  same  conditions  apply  to 
taking  portraits  with  a  short  exposure  in  the  atelier. 

To  any  one  who  wishes  to  make  instantaneous  pictures,  I  would 
recommend  to  place  himself  in  such  a  position  that  the  majority  of 
the  movable  objects  approach  or  move  away  from  the  apparatus.  In 
this  case  the  change  of  position  is  apparently  the  smallest;  in  taking 
a  view  of  a  street  we  should  look  into  the  street  lengthways,  and 
marching  soldiers  we  should  take  in  the  direction  of  the  march. 

TENT  WORK  AND  PHOTOGRAPHIC  EXCURSIONS. 

In  the  previously  described  operations,  the  existence  of  a  labora- 
tory in  which  the  plates  are  prepared  and  developed  has  been  con- 
sidered as  a  matter  of  course.  But .  there  are  plenty  of  cases  where 
such  a  laboratory  does  not  exist,  and  where  pictures  have  to  be  taken 
at  a  distance  from  the  atelier  of  the  photographer.  A  dark-room  has 
to  be  prepared  before  the  photographer  can  commence  to  work.  In 
case  of  necessity  any  inclosed  space  that  can  be  made  light-tight,  can 
be  used  as  a  dark-room.  Braun,  in  Dornach,  does  not  hesitate  to  use 
cellars,  stables,  outhouses,  etc.,  as  dark-rooms,  but  it  always  depends 
on  how  far  we  can  work  here  without  being  molested  by  dust  or 
stench.  As  such  a  space  cannot  always  be  improvised,  the  gravelling 
photographer  will  do  well  to  carry  his  own  dark-room  along.  For 
such  a  portable  room  nothing  is  better  than  a  tent,  which,  above 
everything  else,  must  be  light-tight,  solid,  easily  put  up,  and  suffi- 
ciently comfortable. 

The  number  of  dark-tents  constructed  is  legion.  It  cannot  be  said 
which  is  the  best,  as  it  depends  very  much  on  the  personal  wishes  of 
the  operator,  one  preferring  this  to  the  other  construction.  The  dark- 
tent  should  have  a  table-surface  of  three  or  four  times  the  length  and 
breadth  of  the  plate  to  be  prepared  therein,  easily  and  rapidly  set  up, 
and  not  to  be  too  heavy.  The  sides  of  the  tent  are  therefore  best 
made  of  black  double  English  satinet.  For  light,  a  window  is  made  of 
yellow  Parisian  oiled  silk,  four  thicknesses.    The  tent  represented  in 


TENT  WORK   AND   PHOTOGRAPHIC  EXCURSIONS.  271 


the  annexed  figure,  which  the  author  saw  at  Kilburn's,  in  Littleton,  and 
which  proved  itself  very  serviceable  on  his  tour  to  the  mountains  of  Thu- 
ringia,  consists  of  a  folding  wooden  frame  with  a  plate  B  (Fig.  81),  which 
serves  as  a  work-table,  and 

an  open  top-piece,  A,  which  Fig.  8i. 

is  covered  with  black  cloth. 
The  table  and  top-piece  are 
connected  by  the  hinged 
folding-pieces,  m  m.  When 
the  hooks,  h,  h,  which  fit  into 
the  eyes,  KK,  are  unfastened, 
the  supports,  m  m,  fold  like  a 
pocket-knife,  and  the  frame 
lies  perfectly  flat.  Inside  of 
this  wooden  frame  the  four- 
cornered  tent-cloth  is  fastened.  It  is  nailed  to  the  top-piece,  A,  and 
the  table,  B.  At  H,  Fig.  81,  is  the  window  of  oiled  silk ;  at  V, 
Fig.  82,  is  the  front  curtain 
through  which  the  operator 
has  to  creep  and  seat  himself 
on  the  camp-stool,  S.  At  q, 
Fig.  82,  is  an  opening  for  ven- 
tilation ;  at  x,  Fig.  81,  is  a  large 
opening  in  the  table,  which 
is  lined  with  caoutchouc 
cloth,  and  forms  a  kind  of  a 
dish ;  it  serves  to  receive  the 
developing  solution  as  it 
flows  off  the  plate.  Through  a 
hole  in  the  centre  the  waste 
solution  is  discharged,  and  india-rubber  hose  is  not  absolutely  neces- 
sary. At  the  top  towards  the  left  hand  is  placed  a  hook  to  hang  an 
india-rubber  water-bag  holding  five  litres;  a  gum  hose  is  stuck  in, 
leaving  one  end  hang  down,  forming  a  siphon.  .  It  is  closed  by  means 
of  a  small  squeezing  cock.  The  tent  is  placed  on  four  legs,  b,  b,  b,  b, 
Fig.  82.  These  are  either  screwed  on,  or  they  are  fixed  with  hinges, 
and  fold  under  the  table  ;  binding  screws,  S,  S,  serve  to  fasten  the  legs 
in  position  when  the  tent  is  erected.  When  we  desire  to  fold  the 
tent,  the  curtain,  V,  is  first  pushed  inward,  the  camp-stool  is  placed 
inside  (also  the  feet,  if  these  should  be  arranged  for  unscrewing) ;  the 
hooks,  h,  h,  h,  h,  are  next  undone,  and  the  top-piece,  A,  is  lowered.  The 


Fig.  82. 


272 


THE  PRACTICE  OP  PHOTOGRAPHY. 


tent-cloth  has  ample  room  between  the  supports,  m,  m,  m,  m,  and  is 
protected  by  them ;  the  feet  are  folded,  and  the  whole  is  strapped 
together  by  the  straps,  r,  r,  Fig.  83.   The  straps  serve  also  to  carry  the 

tent,  and  it  may  be  carried  on  the 
back  like  a  knapsack;  size  of 
plate  30  x  20  inches,  weight 
eighteen  pounds,  time  necessary 
to  erect  it  seventy-five  seconds. 

The  tent  is  placed  in  a  shady 
place,  protected  from  the  wind. 
In  very  warm  countries  sprinkling  the  tent-cloth  and  the  bag  contain- 
ing the  silver  bath  with  water  is  an  excellent  way  of  keeping  both  cool. 

A  similar  tent,  and  one  which  is  very  solid,  is  described  by  Ph. 
Remele  in  his  excellent  "Handbook  of  Landscape  Photography." 
The  tent  is  the  invention  of  L.  Herzog,  in  Bremen.  The  most  essen- 
tial part  of  the  whole  tent  is  the  box  necessary  for  the  transport  of 
apparatus  and  chemicals.  The  box  is  opened  and  four  strong  wooden 
legs  are  attached;  on  the  top  a  folding  iron  rod,  a,  is  pushed  into  the 

corresponding  holes  and  fastened  by 
the  rods,  b,  b;  over  the  rods  a  tent" 
cloth  is  thrown,  and  with  hooks  it  is 
fastened  to  the  eyes,  c,  c,  c,  above, 
below,  and  on  both  sides.  The  tent- 
cloth  should  be  double  at  the  sides, 
that  it  may  be  hooked  in  the  interior 
of  the  box  in  a  similar  manner.  At 
the  lower  extremity  the  tent-cloth 
has  an  opening;  the  operator  creeps 
into  it  and  ties  it  light-tight  around 
his  waist.  At  b  there  is  a  door  in 
the  box,  which  can  be  opened  and 
shut,  and  here  a  window  of  oiled 
silk  is  fixed  in. 

The  best  material  for  a  tent  is 
the  so-called  india-rubber  cloth ;  the 
hooks  are  fastened  to  it  with  gum 
bands.  Overhead  a  yellow  window 
of  oiled  silk  is  placed.  This  tent  is 
remarkably  solid,  offers  much  space 
for  working,  and  has,  finally,  the  advantage  that  one  can  work  in  it 
without  wasting  a  drop  of  silver  or  any  other  solution  on  the  floor. 


TENT  WORK   AND  PHOTOGRAPHIC  EXCURSIONS.  273 


Braun,  in  Dornach,  uses  for  the  preparation  of  large  plates  a  tent, 
consisting  of  a  folding-frame,  m  m,  with  a  dark  cloth  thrown  over 
(see  Figs.  85  and  86). 

For  excursions  all  the  other  objects  necessary  for  operating  have 
to  be  taken  along.    I  carry  a  basket  with  a  lid,  which  is  divided  in 


Fig.  85. 


squares ;  in  such  a  basket  all  the  requisites  are  easily  packed,  and  the 
bottles  are  much  less  exposed  to  breakage,  owing  to  the  elasticity  of 
the  basket,  than  they  would  be  in  a  wooden  box.  Four-cornered 


Fig.  86. 


bottles  are  preferable  to  round  ones.  The  packing  of  the  bottles  re- 
quires the  stuffing  in  between  of  some  soft  material ;  the  best  for  this 
purpose  is  rags  or  paper.    (Tow  or  hay  will  make  too  much  dust.) 

I  also,  for  transporting,  make  use  of  a  box  with  a  lid,  having 
several  four-cornered  partitions  lined  with  felt,  in  which  all  bottles 
can  be  easily  packed;  four-edged  bottles  are  preferred  for  this  purpose. 

18 


274 


THE  PRACTICE  OF  PHOTOGRAPHY. 


The  box  contains  on  one  side  a  compartment  with  one  dozen  plates 
7x9,  and  of  all  the  chemicals  used  as  much  as  is  necessary  to  prepare 
them.  The  weight  of  the  box  is  moderate  ;  it  will  answer  fully  for  a 
day's  excursion.  Its  contents  are  easily  replenished,  with  a  stock  of 
chemicals  left  at  the  hotel  while  travelling.  The  quantity  of  chemi- 
cals depends  on  the  size  and  number  of  plates. 

In  Dr.  VogeFs  Pocket  Reference  Book,  the  quantity  of  chemicals 
necessary  for  plates  of  1  square  foot  is  given.  Per  square  foot  (equals 
T\jth  square  metre,  size  of  plate),  25  cubic  centimetres  of  albumen  solu- 
tion is  necessary  (see  Albumenizing).  Silver  bath  according  to  the 
size  of  the  bath-holder  (see  Bath-holder  and  dishes).  Collodion  16 
grammes,  developer  300  cubic  centimetres,  intensifier  48  cubic  cen- 
timetres, fixing  (cyanide)  100  to  150  cubic  centimetres.  Water  to 
wash  before  fixing,  2  litres ;  water  to  wash  after  fixing,  8  litres ;  varnish 
7-J  cubic  centimetres.  If  in  want  of  water,  the  fixing,  washing,  and 
varnishing  are  done  at  home. 

The  following  articles  are  necessary  for  a  photographic  excursion  : 


(a.)  For  short  excursions. 


1.  Tent. 

22. 

Distilled  water. 

2.  Camera  box. 

23. 

Cyanide  of  potassium. 

3.  Tripod  for  same. 

24. 

Some  empty  bottles  and  corks. 

4.  Connecting  screw  for  2  and  3. 

25. 

Varnish  for  negatives. 

5.  Plate-holder,  with  frames. 

26. 

Graduate. 

6.  'Tubes,  with  camera  box  fronts. 

27. 

Two  funnels. 

7.  Focussing  glass. 

28. 

Alcohol. 

8.  Plate  box. 

29. 

Filtering  paper. 

9.  Cleaned  plates. 

30. 

Writing  paper  for  scumming 

10.  Duster. 

the  bath. 

11.  Dipper. 

31. 

Matches. 

12.  Two  focussing  cloths. 

32. 

Scissors  and  knife. 

13.  Water-can  and  rinsing-water. 

33. 

Twine  and  pins. 

14.  Bath  or  dish. 

34. 

Developing  glasses. 

15.  Alcohol  lamp. 

35. 

Bottle  of  nitric  acid  for  acidi- 

16. Photogenic  lamp. 

fying  the  bath. 

17.  Negative  bath. 

36. 

Bottle  of  bichloride  of  mer- 

18. Collodion. 

cury*  for  removing  stains 

19.  Developer. 

from  clothing. 

20.  Silver  for  intensifying. 

37. 

Towels. 

21.  Alcoholic  pyrogallic  solution. 

*  The  sublimed  mercury  is  excellent  for  this  purpose,  as  it  does  not  destroy 
color. 


TENT  WORK  AND  PHOTOGRAPHIC  EXCURSIONS.  275 


These  should  all  be  selected  of  the  very  best  quality.  It  is  poor 
economy  for  a  photographer  to  attempt  to  save  money  on  his  chemi- 
cals. Aim  for  the  best  results,  and  to  secure  them  use  the  best  of 
everything. 

For  longer  excursions,  all  the  above  articles  should  be  taken  along 
in  duplicate,  so  that  in  case  of  loss  they  may  be  replaced,  besides, 


1.  Scales  with  horn  dishes. 

2.  Weights. 

3.  Nitrate  of  silver. 

4.  Sulphate  of  iron  or  sulphate 

of  iron  and  ammonia. 

5.  Glacial  acetic  acid. 

6.  Pyrogallic  acid. 

7.  Citric  acid. 

8.  Plain  collodion. 

9.  Iodizer. 


10.  Salts  of  iodine  for  sensitizing. 

11.  Alcohol  and  ether. 

12.  Nitric  acid. 

13.  Rags  for  cleaning. 

14.  Cleaning  vice. 

15.  Tools    (screws,  screw-driver, 

diamond  for  cutting  glass). 

16.  Permanganate  of  potash  for 

restoring  the  bath. 


The  quantities  of  the  articles  must  depend  on  the  length  of  the  ex- 
cursion. For  excursions  it  is  to  be  recommended  to  test  all  the  mixed 
chemicals  at  home,  and  only  to  take  them  when  they  are  in  perfect 
working  order.  All  the  articles  should  be  compared  with  the  list 
before  starting,  as  it  often  happens  that  thoughtless  people  arrive  at 
their  destination  and  have  to  go  home  again  because  some  simple 
article  was  left  behind. 

That  working  in  the  field  or  tent  requires  much  more  circumspec- 
tion than  in  the  atelier  is  self-evident.  The  difficulties  become  some- 
times insurmountable.  Dust,  heat,  and  the  want  of  suitable  water, 
wind,  cold,  and  unfavorable  weather.  These  very  often  put  the 
patience  of  the  photographer  to  the  severest  test. 

Another  point  is  of  great  importance,  namely,  solid  apparatus 
which  can  easily  be  reduced  to  a  small  compass.  I  will  describe  some 
such  here.  • 

Landscape  photography  is  considerably  more  convenient  with  dry 
plates.  These  require  the  articles  from  2  to  7,  also  12  of  the  first  list; 
a  dark-box  to  change  the  plates  ;  instead  of  the  latter,  several  holders, 
one  plate  in  each  holder.  Of  course,  the  results  of  the  dry  process 
are  not  of  such  a  character  that  they  can  be  placed  alongside  of  the 
wet  process.  In  the  latter  the  result  can  be  known  very  readily,  and 
if  not  satisfactory  the  negative  can  be  retaken,  while  in  the  dry  the 
result  is  first  found  out  at  home. 


276 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Meagher's  Travelling  Camera. — This  camera*  (Figs.  87  and  88) 
which  was  first  constructed  by  a  celebrated  joiner,  consists  of  a  rigid 
front  piece,  v,  which  is  supplied  with  grooves  for  the  reception  of  the 
board  carrying  the  tubes ;  the  back-piece,  H,  H,  is  movable,  and  re- 
ceives the  ground-glass  and  plate-holder.  The  focussing  is  done  by 
the  screw  adjustment,  consisting  of  an  endless  screw,  s,  s,  and  the 


Fig.  87.  fig.  88. 


handle,  g.  The  camera  board,  which  carries  the  whole  arrangement, 
is  divided ;  the  back-piece,  B,  B,  is  at  x  connected  with  the  front  by 
hinges ;  a  folding  support,  S,  with  a  screw,  r,  gives  firmness  to  the 
whole.  For  the  transport,  the  bellows  is  screwed  together,  so  that  H 
and  v  touch  each  other. 

The  board,  S,  is  turned  over,  and  fastened  with  the  screw  at  r. 
Meagher,  as  weU  as  the  American  Optical  Company,  furnishes  square 
as  well  as  rectangular  cameras ;  as  the  first  only  use  lengthy  plates, 
we  see  no  advantage  in  their  use.  The  camera  of  the  author  can  be 
used  for  plates  9  x  7",  and  for  a  focus  of  from  four  to  twelve  inches ; 
has  a  movable  partition  in  the  centre  for  the  production  of  stereoscopic 
pictures,  and  served  five  years  ago  in  the  Egyptian  expedition  with 


*  The  same  and  similar  constructions  are  furnished  in  America  by  the 
American  Optical  Company  in  New  York,  one  of  whose  boxes  I  have  had 
great  pleasure  and  satisfaction  in  using. 


TENT  WORK  AND  PHOTOGRAPHIC  EXCURSIONS.  277 


the  best  success.  The  only  inconvenience  is  want  of  firmness  of  the 
piece  S',  which  is  apt  to  shrink  and  burst  in  very  dry  weather.  To  this 
camera  also  belongs,  besides  the  ordinary,  a  double  holder,  intended 
for  dry  plates.  Camera  holders  and  objectives  we  generally  transport 
in  a  large  tin  chest,  which  is  closed  with  a  strap.  One  man  carries, 
by  means  of  a  strap  or  rope,  the  chemical  box  in  front,  and  the  tin 
chest  on  bis  back,  while  a  second  takes  the  tent  with  tripod  on  his  back. 
In  this  manner  the  author  has  made  the  most  impassable  mountain 
tours.  The  tripod  should  be  solid,  so  as  not  to  shake  in  the  wind.  For 
silvering,  we  prefer  a  Japanese  dish  having  a  tight-fitting  lid,  so  that 
nothing  injurious  may  splash  into  the  silver  bath. 

Others  take  a  travelling  bath-holder.  This  article,  to  be  had 
of  all  dealers  in  photographic  goods,  consists  of  an  ordinary  glass 
bath-holder,  packed  tightly  in  a  wooden  box,  with  lid  lined  with  soft 
india-rubber,  which  can  be  closed  tight  by  means  of  a  screw.  For 
short  excursions  this  arrangement  is  practical.  In  long  excursions 
the  india-rubber  is  apt  to  act  prejudicially  to  the  silver  bath.  For  ob- 
jectives different  instruments  are  used.  For  instantaneous  pictures 
portrait  tubes  are  used,  and  single  landscape  lenses  if  a  little  aberra- 
tion does  not  matter.  Triplets  and  aplanatic,  if  correct  lines,  etc., 
are  desired ;  wide-angled  and  pantoscope,  if  a  large  field  is  desired.  (A 
summary  list  of  the  size,  focus,  size  of  field,  and  price  of  these  instru- 
ments, is  found  in  Vogel's  Pocket  Reference  Book,  published  by  Ben- 
erman  &  Wilson.)  The  large  field  of  the  latter  can  very  often  have 
an  annoying  effect,  when  indifferent  objects  in  the  foreground* are 
brought  into  the  picture,  which,  by  their  large  appearance,  disfigure 
the  picture,  while  the  distance  appears  diminutive  and  small.  (See 
chapter  on  Perspective,  Part  III.)  Often  the  main  object  in  a  land- 
scape lies  in  the  distance,  then  a  long-focussed  lens  should  be  used, 
which  produces  the  distant  objects  large.  The  author  always  takes 
three  objectives  with  him,  a  pantoscope,  whose  length  of  focus  is  half 
as  long  as  the  size  of  the  plate ;  an  aplanatic,  whose  focus  is  nearly 
the  length  of  the  plate ;  and  an  aplanatic,  the  focus  of  which  is  -f 
|  the  length  of  the  plate.  When  arrived  at  the  spot,  he  tries  which 
objective  produces  the  most  favorable  picture.  About  the  point  of 
view,  etc.,  see  part  on  ^Esthetics.  About  annoyance  by  the  public, 
see  next  chapter.  The  methods  of  operation  do  not  differ  from  the 
former  described.  We  use,  on  account  of  its  keeping  qualities,  on 
journeys,  the  equivalent  collodion,  the  sulphate  of  iron  and  ammonia 
(for  developing  and  intensifying),  and  for  fixing,  on  account  of  its 
rapid  action  and  easier  washing,  cyanide  of  potassium.  The  last  drop 
of  water  off  a  plate  after  fixing,  caught  on  the  tongue,  will  disclose 


278 


THE  PRACTICE  OP  PHOTOGRAPHY. 


by  its  bitter  taste  any  insufficient  washing.  If  the  time  or  water  is 
short,  the  plates  are  developed  and  intensified,  put  in  the  plate-box 
without  fixing,  and  finished  at  home.  Albumenized  plates  are  advan- 
tageous. 

SECTION  V. 

ARCHITECTURE  AND  INTERIORS. 

Pictures  of  buildings,  out  and  indoor  views,  present  difficulties 
through  the  point  of  view.  There  is  not  sufficient  distance,  for  in- 
stance, in  a  narrow  street  to  bring  a  building,  or  a  part  of  it,  into  the 
field  of  view  of  the  camera.  Further  difficulties  present  themselves 
in  interiors  by  insufficient  lighting.  In  this  case  long  exposure  or  re- 
flected sunlight  will  help.  (See  remarks  thereon.)  A  not  very  slight 
difficulty  consists  here,  as  well  as  in  landscaping,  i.  e.,  annoyance  from 
the  public.  In  taking  streets,  persons  often  push  forward  in  an  im- 
proper manner,  taking  a  stand  immediately  in  the  foreground.  It 
is,  therefore,  often  impossible  to  make  an  exposure.  If  it  is  an  affair 
of  two  or  three  persons,  a  little  ruse,  or  a  talking  will  help  to  get  rid 
of  them,  and  place  them  in  a  position  outside  of  the  field  of  view. 
With  large  masses  in  streets  this  will  not  answer.  It  is  well  to  be  as 
little  observed  as  possible.  Either  place  your  apparatus  at  a  window 
in  a  room,  to  hide  it  from  the  gaze  of  the  public,  or  place  it  in  a  cov- 
ered furniture  wagon,  in  the  side  of  which  a  hole  is  cut  for  the  objec- 
tive. The  wagon  can  be  properly  placed  without  notice  from  the  pub- 
lic. As  objective  use  only  the  pantoscope  (for  large  angle),  showing 
correct  lines ;  triplets  or  aplanatic  for  smaller  ones.  About  the  most 
important  point,  perspective  and  point  of  view,  see  the  third  Part  of 
this  book. 

SECTION  VI. 

MICROPHOTOGRAPHY. 

The  enlarged  photographs  produced  from  microscopic  objects  are 
called  microphotographs,  to  distinguish  them  from  the  microscopic 
pictures  of  large  objects,  which  are  called  microscopic  photographs. 
The  latter  are  entirely  out  of  fashion.  Formerly  they  were  an  impor- 
tant article  of  trade  of  the  house  of  Dagron,  in  Paris,  who  also  sold 
the  apparatus  for  the  production  of  the  pictures.  They  contained  a 
lens  combination  of  very  short  focus,  which  was  placed  on  a  small 


MICROPHOTOGRAPHY. 


279 


camera  with  a  movable  holder.  This  holder  could  be  moved  ten 
times,  and  produced  from  a  negative  small  transparent  positives, 
which  were  cut  apart,  then  provided  with  a  magnifying  glass,  and 
were  ready  for  the  trade.  During  the  siege  of  Paris,  Dagron  produced 
microscopic  dispatches  on  collodion,  which  were  stripped  off  with 
so-called  leather  collodion,  and  hundreds  of  them  placed  in  a  quill 
and  tied  to  a  carrier-pigeon.  In  this  way  Paris  communicated  pho- 
tographically with  the  outside  world.  Here  we  busy  ourselves  only 
with  microphotography,  which  is  of  some  importance  to  the  natural- 
ist, physician,  and  an  aid  in  instruction  of 


great  consequence.  Microphotographs  are 
best  made  with  the  aid  of  an  ordinary  mi- 
croscope, of  the  same  kind  as  used  by  the 
searcher  in  making  his  observations.  The 
less  there  is  altered  on  it  the  better.  The 
simplest  manner  is  that  of  the  author's.  He 
places  immediately  on  the  microscope  (Fig. 
89)  a  camera,  K,  with  a  landscape  lens,  Q, 
so  that  the  objective  of  the  camera  nearly 
touches  the  ocular  of  the  microscope.  The 
camera  is  supported  by  a  tripod  of  the  re- 
quired height.  If  the  microscope  can  be 
placed  horizontally  the  arrangement  is  still 
easier.  If,  with  the  aid  of  the  concave  mir- 
ror, S  (attached  to  the  microscope),  the  rays 
of  the  sun  are  thrown  on  the  object,  which 
is  placed  at  G  on  a  piece  of  glass,  the  pic- 
ture can  be  plainly  seen  on  the  ground- 
glass.  By  the  aid  of  the  pinion,  M,  it  can 
be  set  sharp ;  the  photographic  exposure 
can  then  take  place,  which  in  bright  sunlight 
will  be  instantaneous. 


This  method  of  making  microphotographs  is  so  simple  that  anyone 
can  practice  it  who  is  at  all  familiar  with  photographic  operations. 
It  requires  no  other  apparatus  than  a  simple  camera  with  a  landscape 
lens.  It  can  be  adapted  to  any  microscope  which  is  sufficiently  strong 
in  light,  and  gives,  accordingly  as  the  ground-glass  is  more  or  less 
removed  from  the  object,  views  which  are  equal,  or  larger  or  smaller, 
than  the  directly  observed  image. 

Two  precautions  should  be  observed  in  making  such  pictures :  The 
lens  of  the  camera  must  not  have  a  chemical  focus,  and  the  picture 
should  be  taken  in  a  room  which  is  not  exposed  to  any  vibration. 


280 


THE   PRACTICE  OF  PHOTOGRAPHY-. 


The  picture  may  also  be  taken  when  the  instrument  is  placed  in  a 
vertical  position.  In  that  case  the  camera  must  also  be  placed  verti- 
cally in  order  that  the  two  optical  axes  coincide. 

I  published  this  method  in  November,  1862,  and  have  frequently 
practiced  it. 

The  illumination  offers  some  difficulty  in  so  far  as  a  quantity  of 
unnecessary  light  is  easily  thrown  into  the  object-glass  of  the  micro- 
scope, which  materially  disturbs  the  purity  of  the  picture.  The  best 
way  to  concentrate  the  light  is  by  placing  the  object  at  the  apex  of  a 
cone  of  rays,  the  axis  of  which  coincides  with  the  axis  of  the  micro- 
scope. With  opaque  objects  this  danger  does  not  exist.  The  illumi- 
nation is  made  with  a  condensing  lens  (bull's  eye). 

The  above-stated  simple  combination  of  the  microscope  and  the 
camera  has  the  other  advantage,  that  the  cobweb  lines  are  visible  in 
every  picture,  and  that  a  difference  in  the  chemical  and  optical  foci 
of  the  microscope  itself  does  not  amount  to  much,  provided  that  the 
camera  lens  is  free  from  this  error. 

But  when  the  cobweb  lines  are  not  necessarily  required,  we  can 
operate  with  the  microscope  alone.  The  microscope  has  two  lens 
combinations,  the  objective  lenses,  I,  I,  which  throw  the  enlarged  pic- 
ture, A,  B,  from  the  object,  a  b,  and  the 
ocular  lines,  o  o,  which  again  throw  an 
enlarged  imaginary  picture  of  the  ob- 
ject, A,  B.  If  the  ocular  is  taken  out, 
and  the  lens,  1 1,  is  moved  nearer  to  the 
object,  the  picture,  A,  B,  will  move  out- 
side of  the  tube  of  the  microscope,  and 
can  be  caught  on  a  ground-glass.  The 
objective  of  the  microscope  can  also  be 
used  as  a  photographic  lens.  The  lens 
of  the  camera,  K,  Fig.  89  is  removed  ; 
the  tube  of  the  microscope,  after  having 
removed  the  eye-piece,  A,  is  placed  in  the 
opening  of  the  camera ;  all  extraneous 
light  is  excluded  by  means  of  a  cloth, 
or  a  sleeve,  which  is  nailed  on  to  the 
camera,  and  its  other  end  tied  to  the  tube  of  the  microscope. 

When  the  micrometer  screw,  My  of  the  microscope  is  now  gently 
turned  in  a  direction  to  remove  the  object  from  the  object-lens,  the 
image  will  appear  on  the  ground-glass  as  the  image  produced  by  the 
objective  of  the  microscope  is  enlarged  and  projected  on  the  ground- 


MICROPHOTOGRA  PHY. 


281 


glass  by  the  eye-piece.  Unfortunately  a  chemical  focus  becomes 
rather  annoying  with  this  method. 

Now  there  is  a  third  method,"  without  changing  the  microscope 
(ocular  included),  to  produce  pictures  on  the  ground-glass.  The  ocular 
end,  A,  is  placed  in  the  camera,  K,  Fig.  89  (after  removing  the  tube  of 
the  camera) ;  now  carefully  turn  the  screw,  Mt  so  that  the  tube  of  the 
microscope  will  move  away  from  the  object,  thereby  the  enlarged 
picture,  A  B,  will  move  away  from  the  ocular,  coming  in  its  focus. 
A  picture  suddenly  appears  on  the  ground-glass,  K,  since  here  the  pic- 
ture thrown  by  the  microscope  objective  is  enlarged  by  the  micro- 
scope ocular.    The  exposure  is  done  in  the  usual  manner. 

By  removing  the  ground-glass  further  from  the  object,  we  enlarge 
the  image. 

The  extent  of  the  chemical  focus  is  easily  ascertained. 

I  employed  a  microscopic  photograph  by  Dancer  of  Konigsberg. 
The  picture  itself  was  an  albumen  positive,  about  the  size  of  a  pin's 
head,  and  placed  between  thin  glass ;  under  a  microscope  with  a  power 
of  one  hundred  diameters,  it  appears  as  a  plain,  legible  inscription — 
the  inscription  on  the  tombstone  of  General  Dickson — which  is  ar- 
ranged in  about  the  following  order : 

(1)  To  the  memory  of 

(2)  William  Francis  Dickson, 

(3)  Major  in  Her  Majesty's  62d  Kegiment 

(4)  of  Foot,  and  eldest  son  of 

(5)  General  Sir  Jeremiah  Dickson,  K.  C.  B. 

(6)  He  died  a  soldier's  death  before  Sebastopol, 

(7)  June  8,  1855,  having  been  killed  early  in 

(8)  the  morning  of  that  day,  whilst  gallantly 

(9)  holding  the  quarries  against  repeated 
(10)  attacks  of  the  Kussians,  etc.,  etc. 

I  laid  this  photograph  on  the  stage  of  the  microscope,  not  flat,  but 
inclined  by  placing  pieces  of  wood  under  one  end.  The  direction  of 
the  lines  remained  horizontal,  but  the  line  vertical  to  it  formed  with 
the  horizontal  plane  an  angle  of  30°.  By  this  arrangement  the  dis- 
tance of  the  lines  from  the  combination  of  lenses  was  a  different  one 
for  each  line,  and  it  was  not  possible  to  focus  sharply  more  than  one 
or,  at  most,  two  lines.  With  the  Schick  combination  of  lenses,  1  +  2 
+  3,  I  focussed  sharply  on  line  8,  and  took  two  pictures.  On  both 
pictures  line  5  appeared  black  and  sharp  instead  of  line  8.  This  de- 
monstrated a  chemical  focus.  To  measure  this  difference,  and  to  com- 
pensate for  it,  I  used  the  micrometer  adjustment  of  Schick's  instrument, 


282 


THE  PRACTICE  OF  PHOTOGRAPHY. 


by  which  the  stage  of  the  instrument  can  be  elevated  or  depressed,  and 
by  which  the  fine  adjustment  is  made. 

From  the  above  experiments  it  becomes  evident  that  in  order  to 
q,btain  a  sharp  picture  of  line  No.  8,  I  must  focus  on  line  No.  5  ;  or  if 
I  focussed  on  line  8, 1  must  turn  the  micrometer  screw  until  line  5  ap- 
peared sharply  defined  in  the  field.  I  have  measured  the  revolutions, 
and  found  that  with  G.  Eose's  microscope  it  amounted  to  50°,  and 
with  Dove's  microscope  to  35°,  for  the  combination  1  +  2  +  3. 

These  measurements  are  easily  made  by  placing  under  the  head  of 
the  micrometer  screw  a  paper  circle,  which  is  divided  by  radii  from 
5°  to  6°,  in  such  a  manner  that  the  centre  of  the  circle  coincides  with 
the  prolongation  of  the  axis  of  the  screw,  and  by  filing  on  the  head 
of  the  screw  a  line  with  a  file.  By  placing  the  eye  vertically  over  the 
head  of  the  screw,  it  is  not  so  very  difficult  to  note  the  change  on  the 
divided  paper  circle. 

After  having  measured  the  focal  difference,  two  new  pictures  were 
taken ;  line  No.  8  was  sharply  focussed,  the  micrometer  screw  was  suf- 
ficiently turned  to  compensate  for  the  chemical  focus,  and  now  line  8 
appeared  sharp  in  both  pictures. 

Another  picture  of  the  whole  slide  placed  horizontally  and  taken 
with  a  magnifying  power  of  25  and  the  above  correction  gave  a  sharp 
picture  of  all  the  lines. 

"With  the  microscope  the  focal  difference  of  every  combination  must 
be  ascertained  by  experiment.  For  low  powTers  the  difference  is  small ; 
a  six-fold  magnifying  power  (lens  1  of  Schick)  shows  scarcely  any 
chemical  focus. 

Benecke  and  Woodward  use  a  solution  of  sulphate  of  copper  and 
ammonia  to  keep  out  the  difference  of  focus.  This  solution  will  only 
permit  the  passage  of  blue  rays.  If  this  solution  is  placed  in  a  glass- 
cell  before  the  collimator  lens,  the  focus  can  be  taken  without  fear  of 
a  chemical  focus.  Woodward  also  uses  artificial  light  for  lighting 
magnesium  and  electric.    He  recommends  the  latter. 

SECTION  VII. 

SPECTRAL  PHOTOGRAPHY. 

It  appears  almost  an  idle  task  to  speak  of  photographing  the  spec- 
trum, and  yet  it  is  of  immense  importance,  not  only  for  the  spectral 
analyzer,  who  through  it  obtains  a  true  picture  of  the  spectral  lines 


SPECTRAL  PHOTOGRAPHY. 


283 


Fig.  91. 


of  the  sun,  which  serve  as  a  vehicle  for  the  determination  of  matter,* 
but  also,  from  the  latest  observations  of  the  author  himself,  for  the 
photographer,  for  by  spectral  photography  the  author  was  led  to 
make  the  discovery,  that  there  are  expedients  existing,  to  make  bro- 
mide and  chloride  of  silver  sensitive  to  light  in  the  red  and  yellow 
rays,  which  have  hitherto  been  considered  chemically  non-actinic.  By 
spectral  photography,  the  author  further  was  enabled  to  make  studies 
on  the  striking  changes  in  the  transparency  of  our  atmosphere,  for 
chemical  actinic  light  of  different  colors  (see  February  number,  1874, 
Photo.  Mittheil.)  ;  further,  about  the  effect  which  the  different  preser- 
vatives and  organic  substances  have  on  the  sensitiveness  of  the  plates. 
For  the  production  of  a  spectrum,  a  spectral  apparatus  will  answer, 
which  consists  of  a  tube,  C(Fig.  91),  in  which  are 
set  two  metal  plates,  S,  allowing  a  slit  between 
them,  which  can  be  widened  or  narrowed  with 
a  screw.  This  slit  is  exactly  in  focus  with  the 
lens,  L,  whose  task  is  only  to  make  the  rays 
parallel  issuing  from  the  slit,  and  to  throw 
them  thus  on  the  prism,  P.  This  separates 
each  ray  into  a  color  fan,  so  to  speak,  and 
such  are  taken  up  by  the  telescope,  F,  the 
lens  of  which,  L' unites  the  various  colors,  each 
for  itself,  and  thereby  a  real  color  picture  is 
formed  in  the  focus  of  the  lens.  This  lies  in- 
side of  the  tube.  This  color  picture  can  either 
be  observed  through  the  ocular,  0,  or  photo- 
graphed. The  camera,  K,  is  placed  for  the 
purpose :  place  the  tube  in  the  opening  for  the 
tube,  draw  a  sleeve  attached  to  the  camera  over  the  tube  to  make  it 
light-tight,  and  pull  the  ocular,  0,  out  a  little  way ;  this  produces  the 
picture  of  the  spectrum  on  the  ground-glass.  If  sunlight  falls  on  the 
slit,  and  it  is  sufficiently  narrow,  the  dark  lines  can  be  seen.  The  nar- 
rower the  slit  the  finer  are  the  lines;  the  color  picture  is,  however, 
dimmer.  This  method  furnishes,  with  an  ordinary  spectral  apparatus, 
pictures,  in  which  the  lines  D  and  G  (see  figure),  are  about  thirty- 
five  millimetres  apart.  If  larger  pictures  are  desired,  an  apparatus 
with  several  prisms  is  used.  The  rays  can  also,  in  such  cases,  be 
photographed  with  the  ordinary  tube  and  camera,  instead  of  the  tele- 
scope.   The  longer  the  focus  of  the  former  the  larger  the  picture. 


*  Details  of  the  photographs  of  the  spectral  lines  by  Rutherfurd  can  be 
found  in  Photographische  Mittheilungeti,  vol.  7,  p.  222. 


284 


THE  PRACTICE  OF  PHOTOGRAPHY. 


The  parts  PL  and  U  must  be  covered  with  a  card-board  covering  to 
keep  off  all  side-light.  To  make  continued  use  of  the  sun,  a  heliostat 
must  be  applied  which  follows  its  course.  The  cheapest  can  be  pro- 
cured of  Spencer,  in  Dublin.  The  price  is  fifty  Prussian  thalers.  The 
processes  used  are  the  ordinary ;  bromo-iodized  collodion  is,  however, 
only  sensitive  to  the  green.  For  taking  the  yellow  and  red  parts, 
bromo-silver  dry  plates  must  be  used  (see  Photo.  MittheiL,  1873, 
December  number.) 

SECTION  VIII. 

ASTRONOMICAL  PHOTOGRAPHY. 

The  photographing  of  stars  has  already  obtained  universal  applica- 
tion ;  1,  To  study  the  changes  on  the  sun's  surface ;  2,  To  fix  the 
phenomena  during  a  total  eclipse  of  the  sun ;  3,  To  obtain  true  pic- 
tures of  the  moon's  surface ;  4,  Taking  of  stars  and  groups  of  stars, 
in  behalf  of  exact  measurement,  which  can  be  accomplished  more 
easily  on  the  photographic  picture  than  in  the  telescope.  Of  course, 
when  such  measurements  are  required,  a  very  accurate  adjustment  of 
the  instrument,  and  freedom  of  focal  difference  are  necessary.  Simpler 
arrangements  will  answer,  if  only  pictures  of  the  protuberances  and 
corona  are  desired.  The  astronomical  telescope  is,  according  to  the  main 
point,  a  long  tube  with  an  object-lens  L  (Fig.  92).    This  will  throw  a 

Fig.  92. 


picture  in  focus  of  a  very  distant  object.  The  longer  the  focus  the  larger 
is  the  picture.  The  picture  of  the  sun  in  a  telescope  of  six  feet  focus  is 
as  large  as  eight  lines.  This  picture  is  either  taken  direct,  if  the 
object  shows  weak  illumination,  or  trembles  slightly  (picture  of  the 
eclipse  of  the  sun,  the  stars,  and  the  moon),  by  placing  the  sensitive 
plate  in  the  focus,  or  the  small  picture  is  enlarged  direct  by  a  small 
lens,  L,  of  short  focus  (Fig.  93).  The  focussing  is  done  at  G  by  means 
of  the  ground-glass.  In  this  manner,  pictures  enlarged  six  times  can 
be  produced  very  easily  by  momentary  exposure.  With  objectives  of 
weak  illumination  the  exposure  is  longer,  and  as  the  stars  move,  the 
telescope  must  follow  their  course ;  it  must  have  an  equatorial  stand, 
i.  e.,  by  means  of  exactly  constructed  clockwork,  to  turn  on  an  axis, 


ASTRONOMICAL  PHOTOGRAPHY. 


285 


which  is  parallel  to  the  axis  of  the  globe.  What  is  necessary  to  ob- 
serve, for  very  accurate  work  of  this  kind,  is  described  by  Rutherfurd, 
the  excellent  American  star  photographer,  having  the  projected  ob- 


servation of  the  transit  of  Venus  in  view,  which,  if  accurately  meas- 
ured, will  give  the  means  of  determining  the  sun's  distance  from  the 
earth.  Such  accuracy  is  not  necessary  for  the  taking  of  ordinary  sun 
spots.    Rutherfurd  says : 

1.  Objective. — The  objective  is  adjusted  according  to  the  chemical 
focus  without  regard  to  the  visible  picture.  I  have  done  this  in  two 
ways  :  first,  by  a  combination  of  crown  and  flint  glass,  with  the  corre- 
sponding curves  to  produce  this  correction  ;  second,  by  placing  to  an 
ordinary  achromatic  objective,  a  lens  with  such  curves  and  such  den- 
sity as  appeared  necessary  for  the  desired  correction.  The  objective 
of  fourteen-inch  opening,  which  I  described  in  the  May  number  of 
Am.  Jour,  of  Science,  1865,  was  constructed  after  the  first  plan,  and  is 
now  in  possession  of  the  National  Observatory  of  the  Argentine  Re- 
public. 

The  thirteen-inch  objective,  which  is  at  present  in  my  observatory, 
was  made  according  to  the  second  manner.  Without  such  exact  cor- 
rection the  photographic  picture  will  not  appear  sharp,  and  conse- 
quently be  useless  for  scientific  purposes. 

2.  Tube  and  Focus. — With  an  objective  of  the  above  description 
it  is  impossible  to  focus  with  the  eye ;  at  all  events  such  a  focus  is  too 
uncertain,  if  great  precision  is  desired  to  depend  on  it.  The  focus 
must  be  found  by  trials;  a  micrometer  screw  must  be  also  attached  in 
such  a  manner  that  when  set  it  can  at  any  time  be  reset.  Wooden 
tubes  are,  on  account  of  uneven  expansion  caused  by  moisture  in  the 
air,  not  to  be  recommended.  I  make  use  of  galvanized  iron,  varnished 
and  furnished  with  three  thermometers.  According  to  the  degree  of 
heat  recorded  by  these,  the  expansion  of  the  iron  is  calculated,  and 
the  focus  reset  by  means  of  the  micrometer  screw. 

I  find  that  the  stars  are  the  best  means  to  determine  the  focus  accu- 
rately. Take  on  one  and  the  same  plate,  one  picture  after  another 
of  one  and  the  same  group  of  stars,  moving  the  plate  after  each  ex- 


FlG.  93. 


0 


286 


THE  PRACTICE  OF  PHOTOGRAPHY. 


posure,  and  judge  from  the  result,  in  which  position  the  sharpest 
picture  was  obtained  on  the  plate.  This  point  is  marked  and  taken  as 
the  focus.  If  the  experiment  is  repeated  in  a  clear  atmosphere,  and 
the  same  focus  found,  it  can  be  taken  with  regard  to  the  temperature 
of  the  apparatus  as  certain  and  correct. 

3.  Camera. — The  placing  of  the  plate  in  the  camera  is  as  usual — 
by  means  of  a  holder.  A  photographic  picture  of  the  sun  has  a  di- 
ameter of  about  one-tenth  of  an  inch  for  each  foot  of  focal  length. 
The  picture  of  the  sun,  as  it  appears  in  the  focus  of  the  objective,  is 
enlarged  by  means  of  an  ordinary  objective  (for  my  telescope  I  use  a 
quarter-size  Harrison  portrait  tube).  There  could  be  by  all  means 
better  objectives  made,  aplanatic,  and  for  the  chemical  rays  corrected, 
while  the  best  portrait  objectives  show  decided  curves,  or  have  a  focus 
which  is  about  midway  between  the  optical  and  chemical,  whereby  a 
part  of  the  sharpness  is  lost  on  each  side.  Until  now  I  have  not  seen 
a  lens  such  as  I  mean  (Steinheil,  in  Munich,  and  Schroeder,  in  Ham- 
burg, have  constructed  such).  There,  where  the  rays  cross  each 
other,  i.  e.,  in  the  principal  focus,  the  simple  instantaneous  shutter, 
M,  is  placed,  i.  e.,  a  plate  rotating  around  d,  having  an  opening  at  0. 
This  is  held  by  the  hook  x  y.    If  this  is  pressed  at  y,  the  spring  F  will 


Fig.  94. 


force  it  past  the  opening  of  the  enlarging  objective,  and  thereby  cause 
an  instantaneous  exposure.  In  the  camera,  directly  in  front  of  the 
exposed  plate,  is  a  very  fine  platinum  wire,  stretched  from,  east  to 
west,  with  a  simple  attachment,  by  means  of  which  it  can  be  made  to 
follow  the  course  of  any  star  or  any  sun-spot  which,  in  consequence 
of  the  rotation  of  the  earth,  crosses  the  field  of  view.  The  shadow  of 
this  wire  marks  itself  on  the  photograph  as  a  very  fine  line,  and  shows 


ASTRONOMICAL  PHOTOGRAPHY. 


287 


if  rightly  adjusted  the  zero-point  of  the  position  (Vogel,  in  Bothkamp, 
has  another  arrangement  to  determine  the  position).  This  of  course, 
providing  that  the  equatorial  apparatus  is  adjusted  to  the  meridian 
and  height  of  the  poles,  finally  corrected  for  the  breaking  of  the  rays, 
in  case  the  pictures  should  not  be  meridional.  Back  of  the  ground-glass 
is  placed,  by  means  of  a  sled,  moving  easily  from  east  to  west,  a  Rams- 
den  loop,  with  which  the  whole  plate  can  be  overlooked  from  one  side, 
to  determine  (about  which  we  will  speak  hereafter),  the  angle  for  any 
great  extension  of  the  plate.  To  avoid  unnecessary  marking  of  the 
picture,  the  following  adjustments  are  necessary: 

1.  Adjusting  the  Objective. — This  is  accomplished  by  means  of 
screws,  which  penetrate  through  the  rim  of  the  objective,  and  are 
turned  and  adjusted  until  the  reflections  in  the  objective  of  the  flame 
of  a  candle,  held  at  a  small  hole  in  the  holder,  fall  on  top  of  each 
other,  as  soon  as  it  can  be  sighted  through  the  blue  part  of  the  flame. 

2.  T*he  Adjustment  of  the  Plate. — This  is  more  important  than  the 
former,  and  is  accomplished  by  means  of  screws  placed  in  the  back 
part  of  the  camera,  where  the  holder  is  placed.  The  operation  is  the 
same  for  every  holder.  If  it  is,  however,  adjusted  to  the  one  furthest 
from  the  objective,  the  enlarging  objective  must  be  removed  during 
the  adjustment.  A  plate  of  ordinary  glass  is  placed  in  the  holder, 
having  the  side  turned  away  from  the  objective  smoked,  to  prevent 
reflection ;  the  other  side  is  covered  with  a  piece  of  dull  black  paper, 
having  a  hole  a  quarter  of  an  inch  in  diameter  in  the  centre,  so  that 
only  a  small  spot  in  the  direction  of  the  optical  axis  is  left  uncovered. 
The  objective  is  closed  with  a  lid,  which  also  has  a  hole  a  quarter  of 
an  inch  in  diameter  in  the  centre.  A  candle  is  now  held  before  this 
hole,  and  the  screws  operated  until  the  flame  can  be  seen  in  the  un- 
covered part  of  the  plate.  This  indicates  that  the  plate  is  at  right 
angles  to  the  axis  of  the  telescope. 

3.  Adjustment  of  the  Enlarging  Objective. — This  also  is  done  by 
means  of  particular  screws,  which  are  operated  until  the  different  re- 
flections of  a  candle-flame,  which  is  held  before  a  small  hole  in  the 
centre  of  the  lid  of  the  first  objective,  appear  one  above  the  other  by 
sighting  them  through  the  blue  part  of  the  flame.  The  size  of  the 
unavoidable  aberration  of  the  enlarging  objective  can  be  determined 
by  two  methods: 

First  Method. — Place  in  the  focus  of  the  objective  an  even  parallel 
glass  plate,  on  which  a  fine-lined  net  is  engraved.  Then  point  the 
instrument  towards  the  sky,  and  make  an  enlarged  picture  of  the 
line-net.    The  net  and  the  enlargement  are  accurately  measured, 


288 


THE  PRACTICE  OF  PHOTOGRAPHY. 


which  measurement  will  conclusively  show  the  aberration  of  the  en- 
larging objective. 

Second  Method. — In  the  place  of  the  plate  intended  for  the  picture 
an  even  glass  plate  is  placed,  having  a  number  of  parallel  lines,  in  the 
direction  of  north  and  south,  and  about  three  minutes,  equatorial 
time,  apart.  Then  set  the  telescope  immovably  near  the  meridian, 
and  close  the  light-opening  to  about  one  inch.  By  this  reduction  the 
picture  of  a  star  can  be  seen  quite  plainly,  notwithstanding  that  the 
objective  is  adjusted  to  its  chemical  focus.  The  transit  of  the  various 
bright  stars  through  all  the  lines  of  the  plate  must  be  observed,  with 
the  aid  of  a  chronometer,  through  the  loop  mentioned  above.  A 
comparison  of  the  transits  with  the  measured  distances  of  the  lines 
from  each  other  will  not  only  show  the  angle-value  of  a  known  length 
on  the  plate,  but  also  the  size  of  the  aberration  produced  by  the  in- 
strument, objective,  and  enlarging  lens  combined. 

Another  method  to  determine  the  angle-value  is  to  photograph  an 
object,  the  distance  of  which  is  known,  i.  e.,  a  building  during  the  day, 
or  two  electric  lights  arranged  for  the  purpose  at  night,  or  a  group  of 
stars,  for  instance  the  Pleiades,  the  distance  of  which  is  very  well  known, 
whereby  with  accurate  measurement  the  desired  value  can  be  ascer- 
tained. In  my  opinion,  the  angle-value  of  a  given  length  on  the 
plate  can  be  ascertained  by  a  combination  of  these  methods  with  such 
accuracy,  if  it  is  not  perfect,  however,  surpasses  that  by  means  of  line 
cross  micrometer  or  in  fact  all  astronomical  measures. 

In  behalf  of  pictures  of  the  sun  I  would  mention  that  the  edge  of 
the  sun  cannot  be  used  for  measurement  of  certainty.  A  photograph 
of  the  sun  appears  at  times  larger,  then  smaller,  according  to  the 
intensity  of  the  rays  which  produced  the  picture.  The  cause  of  this 
irregularity  is  change  in  size  of  the  light-opening  of  the  objective  in  the 
time  of  exposure,  transparency  of  the  atmosphere,  the  time  of  day,  or 
the  too  great  sensitiveness  or  insensitiveness  of  the  chemicals.  The 
sun  has  generally  no  sharp  positive  outline,  but  is  in  the  most  aus- 
picious case  an  irregular,  boiling,  eternally  restless  object,  not  at  all 
suitable  for  a  starting-point  in  an  accurate  measurement.  While  in 
all  optical  measurement  we  are  confined  to  a  small  part  of  the  sun's 
edge,  photography  produces  the  whole  of  the  sun's  surface.  It  can,  in 
regard  to  the  average  condition  of  the  outline,  be  accurately  centred, 
and  permit  in  this  manner  of  more  accurate  measurement. 

In  photographing  the  transit  of  Venus,  the  picture  of  Venus  will 
certainly  appear  sharp,  facilitating  easy  and  exact  measurement.  Its 
position,  however,  must  be  determined  from  the  centre,  aud  not  from 
the  edge  of  the  sun. 


ASTRONOMICAL  PHOTOGRAPHY. 


289 


In  photographing  fixed  stars  the  following  must  be  observed :  A 
good  objective,  set  in  an  equatorial  telescope,  which  is  moved  by  a 
correct-going  clockwork,  produces,  by  sjiort  exposure,  the  pictures  of 
large  stars  as  small  round  spots,  which  can  only  be  seen  by  means  of 
a  loop.  In  longer  exposures  the  size  depends  finally  on  the  more  or 
less  vibration  of  the  atmosphere,  which  is  also  the  cause  of  the  flick- 
ering and  twinkling  of  the  stars.  With  eight  minutes'  exposure  stars 
of  the  ninth  magnitude  are  photographed.  These  are  ten  times  weaker 
than  the  weakest  which  can  be  seen  on  a  clear  night  with  the  naked 
eye.  Their  pictures  appear  as  very  small  spots.  It  would  be  very 
hard  to  discern  these  from  dirt-spots  on  the  plate.  The  telescope  is 
therefore  placed  in  a  different  position  after  the  first  exposure,  and  a 
second  exposure  made,  also  of  eight  minutes,  the  clockwork  in  the 
meantime  being  kept  in  motion,  to  lead  the  telescope  in  the  right  di- 
rection. There  will  be  on  the  plate  two  pictures,  close  to  one  another, 
of  each  star,  distance  and  relative  position  being  by  all  the  same. 
These  double  pictures  are  easily  found  on  the  plate,  and  as  such  dis- 
cerned from  dirt-spots.  When  the  telescope  stops,  the  pictures  of  the 
stars  will  certainly  make  a  movement.  Bright  stars  will  therefore 
produce  stripes  or  streaks,  like  walking  persons  in  a  landscape.  This 
streak  is  of  great  importance  to  determine  the  direction  from  east  to 
west  on  the  plate.  For  dim  stars,  which  leave  no  trace  of  a  streak,  a 
third  exposure  is  necessary  to  determine  the  direction.  This  is  done 
after  stopping  the  telescope  a  few  minutes. 

The  polar  axis  of  the  telescope  has,  if  ever  so  nicely  and  carefully 
balanced,  a  certain  degree  of  resistance  to  the  movements,  therefore 
the  clockwork  to  move  it,  to  produce  an  even  motion,  must  be  of  a 
peculiar  and  exact  construction.  If  the  picture  of  a  star  moves  dur- 
ing the  exposure  it  will  not  appear  round  but  oval.  As  the  measure- 
ments must  be  determined  from  the  centre  of  the  picture,  it  must  be 
completely  round.  The  movement  of  the  stars  is,  moreover,  not  fully 
regular,  to  be  sure,  in  consequence  of  the  breaking  of  the  light  by  the 
atmosphere.  The  light  coming  from  a  star  is  led  away  by  our  atmos- 
phere, the  star  appearing  higher  than  it  is  in  reality.  This  difference 
between  appearance  and  reality  is  in  no  manner  regular,  it  changes 
continually  in  the  up  and  down  movement  of  the  stars ;  it  can  be  com- 
puted, however,  after  a  somewhat  complicated  rule  for  each  star, 
according  to  its  height  above  the  horizon.  The  clockwork  in  motion 
for  a  telescope  can  only  be  adjusted  for  a  regular  motion ;  the  time, 
therefore,  for  a  photographic  exposure  must  be  chosen  that  the  break- 
ing of  the  light  with  the  star  in  question  is  as  nearly  regular  as  pos- 
sible for  eight  minutes ;  the  rapidity  of  the  clock  must  be  regulated 

19 


290 


THE  PRACTICE  OF  PHOTOGRAPHY. 


accordingly.  In  this  manner  the  movement  of  the  picture  of  the 
star  can  be  reduced  to  less  than  one  ten-thousandth  of  an  inch  dur- 
ing an  exposure  of  eight  minutes  (Schultz-Sellack,  Photographische 
Mittheilungen,  1873,  p.  200).  A  great  obstacle  for  accurate  measure- 
ments on  photographic  plates  is  the  contraction  of  the  collodion  film. 
The  picture  has  when  wet,  according  to  Paschen,  different  dimensions 
than  when  dry,  and  therefore  recommends  the  placing  of  a  glass  mi- 
crometer plate  in  the  main  focus,  in  which  lines  are  etched  crossways 
at  exactly  equal  distances  from  each  other.  These  are  photographed 
along  in  the  enlargement,  and  as  the  distances  are  known,  the  posi- 
tion of  each  point  can  readily  be  determined,  no  matter  if  the  film 
shrinks  or  not.  In  exposures  with  the  main  focus  this  method  is  not 
applicable. 

A  peculiar  manner  of  photographing  the  sun  is  practiced  by  Win- 
lock,  in  Boston.    He  has  a  stationary  telescope,  B,  Fig.  95,  with  a 


Fig.  95. 


lens,  L,  of  forty  feet  focus,  one  end  being  in  the  dark-room,  where  is 
placed  the  holder,  H.  In  front  of  the  telescope  is  placed  a  heliostat, 
S,  with  reflector,  m,  which  throws  the  rays  of  the  sun  on  the  lens.  A 
board,  Q,  is  held  in  front,  and  rapidly  moved  across,  thereby  causing 
the  exposure.  (See  Photographische  Mittheilungen,  vol.  vii,  p.  226.) 

The  English  prefer,  for  their  astronomical  photographs,  reflecting 
telescopes.  Warren  made  his  moon  and  eclipse  pictures  with  one. 
The  wet  process  and  portrait  collodion  are  generally  used.  H.  C. 
Vogel,  in  Bothkamp,  prefers,  however,  the  dry  process.  He  uses  al- 
bumen plates  according  to  an  old  formula  given  us  by  Fothergill. 
This  is  similar  to  the  one  given  above  of  England's.  The  plates  are 
rubbed  over  on  the  back  with  gum  and  lampblack,  to  prevent  reflec- 
tions from  the  back.  The  lower  edges  of  the  plates  are  ground 
straight.  To  fix  this  lower  edge  to  the  position  of  the  sun,  a  piece  of 
ground-glass,  having  its  edges  ground  straight,  is  placed  in  the  holder, 
so  that  it  will  rest  firmly  against  two  small  pieces  of  glass  placed 
there.  The  camera  is  turned  until  a  picture  of  the  sun's  reflection  is 
caught  exactly  on  a  line  running  parallel  with  the  lower  edge.  If 


ASTRONOMICAL  PHOTOGRAPHY. 


291 


the  sensitive  plate  is  placed  there  in  the  same  manner,  the  lower  edge 
will  be  parallel  to  the  sun's  movement.  The  instantaneous  shutter  is 
put  in  operation  by  means  of  a  galvanic  battery.  (For  further  par- 
ticulars see  "  Beobachtungen  auf  der  Sternwarte  zu  Bothkamp,"  by 
H.  C.  Vogel,  Leipzig,  Engelman.) 

In  respect  to  the  time  of  exposure  in  astronomical  photographs,  we 
would  add  that  this  depends  very  much  on  the  transparency  of  the 
atmosphere.  With  an  objective  of  one-twelfth  relative  opening,  it 
needed  five  seconds  for  taking  the  protuberances  of  the  corona,  which 
is  considerably  dimmer,  about  eight  times  as  long  ;*  for  taking  the 
moon,  five  seconds  (Rutherfurd  in  a  clear  atmosphere  exposed  three- 
quarters  second  for  his  moon  photographs).  All  these  exposures  are 
applicable  to  the  main  focus  of  the  telescope. "  Pictures  of  the  sun 
need  only  momentary  exposure,  even  in  enlargements  or  dim-lighted- 
telescopes. 


*  In  Syracuse,  a  photographic  objective  of  three  feet  focus  was  used  for 
photographing  the  corona,  which,  of  course,  will  admit  of  quicker  exposure. 


THE  ART  OF  PHOTOGRAPHY, 

OR 


PHOTOGRAPHIC  ESTHETICS. 


The  photographic  pictures  which  are  obtained  by  the  previously- 
described  processes  are  made  for  very  different  purposes.  They  are 
either  of  a  purely  scientific  or  technical  nature,  such  as  pictures  of 
microscopic  objects,  representations  of  machinery  or  buildings,  archi- 
tectural plans,  etc.  In  such  cases  their  object  is  to  instruct.  Again, 
a  real  practical  use  is  made  of  them  when  they  furnish  the  basis  for 
measurements,  when  used  as  aids  in  the  construction  of  maps,  or  when 
buildings  are  erected  according  to  the  delineations  which  they  repre- 
sent. Finally,  some  of  the  pictures  obtained  are  of  an  artistic  nature, 
and  then  they  have  no  other  object  than  the  one  to  please;  and 
amongst  representations  from  nature  we  have  to  class  portraits  and 
landscape  pictures  in  this  category. 

The  question  whether  photography  is  an  art  or  not  is  an  idle  one. 

Experience  has  demonstrated  that  a  sharp  and  spotless,  or  in  short 
a  technically  perfect  photograph,  be  it  portrait  or  landscape,  may 
appear  on  the  one  hand  untrue,  or  it  may  displease  when  the  obser- 
vance of  the  laws  of  the  beautiful  (which  are  the  cause  of  our  pleasure 
in  the  works  of  the  plastic  art  or  paintings)  have  been  disregarded. 
That  these  laws  in  their  generality  are  not  applicable  to  photography, 
which  more  than  any  other  art  is  "glued  to  the  substance,"  is  evi- 
dent. 

The  photographer  cannot  follow  his  mind's  ideal  flight.  The  chil- 
dren of  his  creative  fancy  enchant  us  not  in  marble,  nor  do  they  charm 
us  with  brilliant  hues  on  the  canvas,  but  his  aim  is  to  portray  nature ; 
and  the  most  which  can  be  demanded  of  him  is  a  beautiful  reality, — 
truth  in  a  pleasing  form. 

Let  us  see  now  how  nearly  photography  gives  us  truth. 


PHOTOGRAPHY  AND  TRUTH. 


293 


PHOTOGRAPHY  AND  TRUTH. 

Admirers  of  photography  assert  so  often  that  this  young  art  repre- 
sents the  pure  truth,  the  true  counterpart  of  nature.  Photography 
can,  indeed,  when  rightly  applied,  produce  truer  pictures  than  any 
other  art,  but  they  are  not  absolutely  true,  and  because  they  are  not 
absolutely  true  it  becomes  important  to  learn  the  sources  of  error,  and 
they  are  manifold. 

Let  us  first  consider  the  optical  errors. 

A  picture  which  has  been  taken  with  a  lens  that  does  not  delineate 
correctly,  and  causes  the  marginal  lines  which  should  be  straight  to 
appear  curved,  can  certainly  not  be  called  a  correct  one.  Many 
persons  may  not  notice  these  distortions,  nevertheless  they  exist. 
Some  will  say  that  a  correctly  drawing  lens  will  avoid  these  errors. 
True,  very  true;  but  let  us  examine  the  pictures  of  high  buildings 
which  have  been  taken  with  such  a  lens  from  a  low  standpoint. 

TJie  lines  which  should  be  vertical  will  converge  towards  the  top. 
Can  this  be  called  correct?  But  you  will  say  the  reason  of  this  is 
that  the  camera  was  not  placed  level.  Very  good ;  but  let  us  now 
try  a  Globe  or  Pantascopic  lens,  and  take  a  view  of  a  long  street :  how 
the  perspective  deepens;  how  enormously  large  the  nearer  houses  ap- 
pear, and  how  very  small  are  the  objects  in  the  distance.  Houses 
that  are  a  hundred  feet  distant  look  as  if  they  were  half  a  mile 
away.  Is  this  truth?  No,  certainly  not;  and  yet  the  lens  draws 
correctly,  the  camera  has  been  placed  exactly  on  a  level,  and  the  per- 
spective is  mathematically  correct.  A  draughtsman  could  not  make 
it  any  better. 

But  where  lies  the  mistake?  The  angle  of  vision  is  too  large. 
Unfortunately,  this  cannot  always  be  avoided,  and  curious  enough  it 
affects  straight  lines  as  well  as  curved  ones.  Take,  for  instance,  a 
pile  of  cannon-balls.  An  artist  would  represent  the  balls  as  circles^ 
Now  take  a  picture  of  them  with  a  wide-angle  lens,  in  such  a  manner 
that  they  will  appear  at  the  edge  of  the  picture,  and  instead  of  circles 
we  will  have  ellipses.  Mathematically,  this  is  easily  explained.  From 
every  ball  (A  B  C,  Fig.  96),  a  conus  of  rays  proceeds  to  the  optical 
centre  of  the  lens,  o,  and  the  plane  of  the  picture  intersects  them  as  an 
ellipse,  when  it  falls  in  any  other  direction  but  at  right  angles  (see  the 
chapter  on  perspective). 

A  photographer  showed  me  the  view  of  a  castle  which  had  been 
taken  with  a  Globe  lens.  In  front  of  the  castle  was  a  row  of  statues, 
and  it  was  really  comical  to  notice  how  the  bodies  and  faces  grew 
broader  towards  the  edge  of  the  picture,  and  the  slender  Apollo  de 


294 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Belvidere,  who  unfortunately  happened  to  be  at  the  extreme  edge  of 
the  plate,  had  such  a  broad  face,  and  his  body  showed  such  a  remark- 
able rotundity,  that  he  looked  like  Dr.  Luther. 


Fig.  96. 


Now,  is  this  truth  ?  Unfortunately  these  are  not  the  only  sources 
of  error ;  there  are  a  great  many  more. 

Further  on  in  this  book,  I  publish  four  heads,  portraits  of  the  same 
person.  They  were  taken  by  Loescher  &  Petsch,  of  Berlin,  with 
front-light,  top-light,  side-light,  and  oblique-light.  In  the  first  picture 
the  man  looks  dull  and  stupid ;  the  second  gives  him  an  angry  and 
savage  expression ;  the  third  gives  him  a  cunning  look ;  which  of  the 
three  named  pictures  is  the  true  one?  Not  one  of  them.  The  truest 
representation  is  No.  4,  where  a  combination  of  light  effects  has  been 
employed,  and  we  see  that  the  mode  of  lighting  can  also  become  a 
source  of  error.  This  not  only  holds  good  for  portraits,  but  refers  to 
landscapes  also.  The  view  from  the  Rochusberg,  in  Bavaria,  had 
often  been  described  to  me  as  most  beautiful.  Accompanied  by 
friends,  I  visited  the  spot  several  times,  but  we  could  not  see  any 
beauty  in  the  view.  At  last  I  visited  it  again,  not  as  before  in  the 
morning,  but  in  the  evening,  and  then  the  view  was  charming.  But 
besides  the  direction  of  the  light  being  a  source  of  error,  there  is 
another  circumstance  which  has  much  influence  on  the  correctness  of 
photographic  pictures. 

Generally  speaking  the  lights  are  too  white  and  the  shadows  are  too 
black  in  photographic  representations.  This  is  a  radical  error,  which 
has  its  origin  in  the  nature  of  the  art,  and  the  avoidance  of  which  be- 
comes sometimes  very  difficult.  The  error  is  most  striking  in  taking 
the  picture  of  an  object  on  which  the  sun  shines  with  full  force,  for 


PHOTOGRAPHY   AND  TRUTH. 


295 


instance  a  statue.  If  we  expose  for  a  short  time  only  we  get  the  de- 
tails of  the  light  parts,  but  the  shadow  is  a  black  spot  without  any  de- 
sign. If  we  expose  for  a  long  time  we  will  get  some  detail  in  the 
shadows,  but  the  lights  will  be  over-exposed  to  such  an  extent  that  all 
the  finer  shades  will  be  missing.    Is  this  truth  ? 

These  are  the  reasons  why  we  have  so  much  difficulty  in  our  studios 
when  we  wish  to  produce  a  properly  lighted  picture.  We  keep  the 
lights  more  diffused  and  the  shadows,  lighter  than  what  painters  would 
do,  and  the  latter  are  often  surprised  when  they  see  a  model  in  the 
gallery,  under  such  artistically  faulty  illumination,  yield  a  picture 
correct  in  lights  and  shadows. 

In  taking  landscapes,  architectural  objects,  and  particularly  inte- 
riors, we  cannot  control  the  light  with  the  same  ease  as  in  portraiture. 
I  once  photographed  a  chemical  laboratory.  The  room  was  large, 
with  an  arched  ceiling.  In  the  picture  you  can  see  the  tables,  fur- 
naces, retorts,  lamps,  etc.,  everything  perfectly  plain  except  the  arched 
ceiling;  this  was  too  dark. 

I  made  other  attempts  with  twenty,  thirty,  and  even  forty  minutes' 
exposure;  at  last  I  saw  a  trace  of  the  ceiling,  but  now  the  objects  near 
the  windows  were  so  much  over-exposed  that  all  the  details  were  lost. 
The  result  was  four  pictures,  not  one  of  which  was  true.  Finally  I 
resorted  to  throwing  reflected  sunlight  on  to  the  ceiling. 

This  circumstance,  that  photography  reproduces  the  dark  parts  too 
dark,  makes  itself  felt  in  very  simple  operations,  for  instance  in  the 
reproduction  of  prints.  A  photographer  reproduced  Kaulbach's 
"  Battle  of  the  Huns."  The  copy  was  an  excellent  one,  but  the  back- 
ground, was  too  dark,  too  thick,  not  hazy  enough.  The  copy  was  re- 
fused, and  another  picture  demanded. 

The  photographer  now  gave  a  longer  exposure.  The  background 
had  the  hazy  appearance  of  the  original,  but  unfortunately  the  figures 
in  the  foreground,  which  should  have  been  bold  and  black,  had  a 
dusky  gray  look.  Is  this  truth  ?  The  artist  succeeded  finally  by  re- 
touching the  negative. 

I  have  purposely  selected  simple  examples  to  prove  my  assertion, 
that  it  is  difficult  to  make  truthful  photographs.  But  now  comes  the 
worst  point  of  all,  the  different  colors.  In  photography  the  cold  tones 
will  be  rendered  too  light,  while  the  warm  ones,  such  as  red  and 
yellow,  will  be  reproduced  too  dark.  As  an  illustration  I  may  men- 
tion the  photographic  copy  of  Hildebrand's  painting,  "  Sunset  on  the 
Ganges  " — a  glowing  red  sun  with  burning  clouds  of  chrome  yellow  on 
an  ultramarine  blue  sky.  And  now  what  does  the  photograph  show  ? 
A  black  disk  surrounded  by  black  thunder-clouds.    The  sun  looks 


296 


THE  PRACTICE  OF  PHOTOGRAPHY. 


like  the  solar  eclipse  at  Aden.  Is  this  truth?  Still  more  striking 
becomes  the  lack  of  truthfulness  in  photography  when  the  artist  at- 
tempts the  solution  of  a  higher  artistical  problem.  Perhaps  the 
reader  knows  the  pretty  little  picture  called  "  A  Mother's  Love." 
A  young  mother,  in  modern  costume,  sits  in  an  arm-chair  reading ; 
her  little  son  approaches  from  behind,  and,  standing  on  a  chair,  em- 
braces her.  Surprised  and  delighted  the  mother  drops  her  book  and 
kisses  the  child. 

A  photographer  took  it  into  his  head  to  reproduce  the  picture  from 
living  models.  He  easily  found  a  pretty  girl  suitable  to  represent  the 
mother.  A  boy,  a  chair,  some  decorations,  and  furniture,  were  not 
hard  to  procure,  and  the  group  was  placed  in  position.  The  mother 
in  effigy  readily  complied  with  the  directions  of  the  artist,  and  made 
a  face  which  perhaps  might  express  motherly  affection.  The  boy, 
however,  had  different  ideas.  He  did  not  feel  himself  drawn  towards 
his  pseudo  mother,  and  protested  energetically  against  any  familiarity. 
It  required  a  good  sound  thrashing  to  bring  him  to  terms.  With 
these  preliminaries  time  had  been  lost.  The  mother  begins  to  feel 
uncomfortable  in  her  forced  position,  with  the  head  partially  turned 
backwards,  and  finally  the  photographer  "fires  away."  The  picture  is 
sharp,  fully  exposed,  without  spot  or  blemish.  The  models,  to  their 
great  joy,  are  discharged.  A  print  is  made,  and  what  is  the  result? 
The  boy  embraced  the  mother  with  a  face  in  which  the  thrashing  is 
plainly  visible,  and  with  a  look  that  seems  to  indicate  a  desire  to 
choke  her,  while  the  mother  looks  much  more  like  saying,  "  Charley, 
you  are  very  naughty  to  interrupt  my  reading,"  instead  of  "  Dear 
little  pet."  Can  any  one  say  that  such  a  picture  expresses  the  inten- 
tion of  the  photographer?  Is  the  above-described  an  expression  of 
the  title  "  A  mother's  love  ?"  Any  one  will  fail  to  see  the  intention 
of  such  a  picture.  The  whole,  although  a  true  copy  of  the  group  as 
placed  before  the  camera,  is,  as  an  expression  of  a  mother's  affection, 
a  photographic  lie. 

Such  pictures  we  find  by  the  thousand.  Ten  years  ago  these  sins 
were  committed  over  and  over  again  by  the  makers  of  stereograms, 
and  when  such  pictures  meet  with  approval  we  can  only  blame  the 
corrupted  taste  of  the  public  for  it.  But  it  will  be  said  that  the  pho- 
tographer cannot  be  blamed  for  the  lack  of  truth  in  such  a  picture. 
His  models  should  be  censured  for  it.  Still  it  is  the  fault  of  the  pho- 
tographer. Pictures  in  which  the  models  do  not  absolutely  come  up 
to  the  intentions  of  the  artists  should  not  be  made  at  all.  They  do 
not  lie  within  the  province  of  photography. 

But  there  are  other  characteristic  cases  of  photographic  untruth  for 


PHOTOGRAPHY  AND  TRUTH. 


297 


which  the  models  cannot  be  blamed.  Stimulated  by  the  beautiful 
pictures  of  Claude,  Schirmer,  or  Hildebrandt,  a  photographer  attempts 
to  take  a  sunset.  Of  course  the  brilliant  glowing  sun  requires  only  a 
very  short  exposure ;  what  kind  of  a  picture  will  he  get  ?  A  round, 
white  spot  surrounded  by  some  glowing  clouds  will  be  all  that  is  visi- 
ble. All  the  objects  in  the  landscape — trees,  houses,  men — are  all 
totally  under-exposed.  The  road,  the  village,  the  wood,  and  the 
meadow,  all  so  beautiful  to  the  eye,  are  nothing  but  a  confused  black 
mass  without  any  outline.  Is  such  a  picture  true  ?  Even  the  enthu- 
siast in  photography  will  not  dare  to  say  yes. 

Cases  where  glaring  contrasts  in  light  and  shade  make  the  product 
tion  of  a  true  picture  impossible  are  very  numerous.  Most  of  the 
photographs  of  the  Royal  Monument  in  the  "  Thiegarten  "  belong  to 
this  class.  The  monument  is  beautiful,  but  the  background  of  the 
trees  is  without  detail,  without  half  tones,  an  undefined  mass,  any- 
thing but  a  representation  of  the  splendid  foliage  which  charms  the 
eye  at  this  spot. 

Still  more  numerous  are  the  photographs  of  rooms,  where  the  cor- 
ners in  which  objects  are  plainly  visible  to  our  eye  are  represented  by 
pitch-dark  night.  Other  cases  of  photographic  untruth  are  still  more 
characteristic. 

Observe  that  mountain  scene.  A  village  inclosed  on  either  side  by 
wooded  hills  occupies  the  middle  ground.  Houses  are  picturesquely 
scattered  amongst  the  trees  on  the  hillside.  A  chain  of  finely  curved 
mountains  in  the  distance,  the  peaks  of  which  are  glowing  in  the 
evening  sunshine,  forms  the  background  of  this  wonderful  picture. 
Only  one  thing  is  annoying.  A  dilapidated  pigsty,  and  next  to  it  a 
heap  of  straw,  are  in  the  immediate  foreground.  A  painter  who  would 
paint  this  picture  would  either  omit  the  objectionable  feature  altogether, 
or  keep  it  so  subdued  that  it  would  barely  be  noticed. 

How  is  it  with  the  photographer?  He  cannot  remove  the  sty.  He 
looks  for  a  different  standpoint ;  but  now  the  trees  cover  a  large  por- 
tion of  the  landscape.  He  takes  the  view,  sty,  and  all,  but  what  kind 
of  a  picture  will  he  get  ?  The  sty,  which  is  in  the  immediate  fore- 
ground, on  account  of  its  proximity,  appears  of  gigantic  size.  The 
distant  landscape,  the  main  object,  is  small  and  insignificant.  Still 
worse  is  the  effect  of  the  pile  of  straw  in  front  of  the  sty.  It  occupies 
one-fourth  of  the  whole  composition. 

Being  the  most  brilliant  object  in  the  whole  picture,  it  draws  at 
once  the  eye  of  the  spectator  and  calls  it  away  from  other  more  im- 
portant points.  The  effect  is  unpleasant.  It  annoys  the  photographer, 
and  does  not  appear  to  be  a  representation  of  the  landscape  for  which 


298 


THE  PRACTICE  OP  PHOTOGRAPHY. 


it  was  intended,  but  a  picture  of  the  pigsty.  The  secondary  matter 
has  become  the  main  object,  and  if  any  one  writes  under  such  a  pic- 
ture "  A  View  of  Dornburg,"  it  is  simply  untoue.  It  is  untrue,  not 
because  the  objects  represented  do  not  exist  in  nature,  but  because  the 
secondary  matter  is  represented  too  plainly,  too  glaring,  and  too  large, 
and  the  principal  objects  appear  dim  and  unimportant. 

We  now  touch  a  sore  spot  in  photography;  it  draws  the  main  objects 
and  secondary  matters  with  equal  distinctness.  To  the  plate  every- 
thing is  indifferent,  while  the  true  artist,  in  producing  pictures  of 
nature,  will  give  prominence  to  the  characteristic  points,  and  subdue 
and  moderate  the  secondary  matters.  With  artistic  freedom  he  can 
act  and  do  as  he  feels  best,  and  he  is  fully  justified  in  doing  so  ;  for  as 
he  gives  the  characteristic  points  only,  and  suppresses  what  is  secon- 
dary, his  work  will  appear  more  true  than  photography,  which  repro- 
duces everything  with  equal  distinctness,  and  sometimes  gives  the 
greatest  prominence  to  the  most  trifling  matter. 

Reynolds,  in  speaking  of  the  portrait  of  a  lady,  where  an  elabor- 
ately painted  apple  tree  forms  the  background,  says,  it  is  the  picture 
of  an  apple  tree,  and  not  of  a  lady.  The  remark  is  applicable  to  a 
great  many  photographs.  It  is  a  cardinal  fault  that  they  elevate 
secondary  matter  to  the  most  prominent  position.  We  see  a  conglom- 
eration of  bright  furniture,  and  only  on  close  inspection  we  will  find 
that  a  man  is  placed  amongst  it,  for  whose  portrait  the  picture  is  in- 
tended. We  notice  a  white-spotted  dress,  and  finally  discover  that  it 
belongs  to  a  girl  whose  head  is  just  visible.  We  see  a  park  with 
fountains  and  other  fixings,  and  on  very  close  inspection  we  notice 
the  black  coat  of  a  man  dimly  contrasting  with  a  piece  of  dark  shrub- 
bery. 

Perhaps  some  will  raise  a  great  outcry  when  I  ascribe  greater  truth- 
fulness to  the  unrestrained  art  of  painting  than  to  photography,  which 
generally  is  considered  the  most  truthful  of  all  the  picture-producing 
methods.  That  I  refer  only  to  the  works  of  first  class  artists  is  a 
matter  of  course,  and  it  is  one  of  the  greatest  merits  of  photography 
that  it  has  made  the  daubs  of  art,  which  were  formerly  sold  at  every 
corner,  an  impossibility.  I  consider  it  my  duty  to  call  attention  to 
the  sources  of  untruth  in  photography.  Only  when  we  have  learned 
to  know  them,  and  to  appreciate  them,  will  we  learn  also  to  avoid 
them ;  and  those  who  have  been  taught  to  watch  for  them  feel  sur- 
prised and  astonished  how  problems  of  the  most  simple  nature  offer 
difficulties  in  regard  to  truth. 

It  is  the  duty  of  the  photographer  to  weigh  all  the  difficulties  which 
he  has  to  encounter  in  the  production  of  a  truthful  picture.    His  pic- 


PHOTOGRAPHY  AND  TRUTH. 


299 


ture  to  be  true  must  give  prominence  to  the  characteristic  points,  and 
such  as  are  secondary  must  be  made  subordinate.  The  insensible 
plate  of  iodide  of  silver  cannot  do  this.  Controlled  by  immutable 
laws,  it  delineates  everything  that  is  presented. 

The  photographer  accomplishes  his  purpose  partly  by  a  suitable 
preparation  of  the  original,  partly  by  a  proper  treatment  of  the  nega- 
tive. It  is  necessary,  however,  that  he  should  know  the  characteristic 
and  secondary  points  of  his  model.  He  that  has  not  got  an  eye  for 
these  is  not  a  photographic  artist. 

As  the  sculptor  and  painter,  in  order  to  produce  a  lifelike  and 
beautiful  picture,  must  pay  attention  to  the  minutest  details  of  every 
feature  of  the  face,  every  effect  of  light  and  shade,  every  fold  in  the 
drapery,  so  must  the  photographer  study  his  model  as  closely  as  pos- 
sible in  features,  carriage,  and  dress.  The  forte  of  the  two  arts,  paint- 
ing and  photography,  is  however  entirely  different. 

The  object  of  both  is  to  produce  a  beautiful  picture  on  a  plane  sur- 
face, which  must  not  appear  flat,  but  round  and  real. 

The  painter  can  produce  upon  his  canvas  from  an  imperfect  model 
an  artistically  beautiful  picture,  and  improve  upon  the  original  by 
idealizing.  The  photographer  has  to  work  differently.  He  cannot, 
like  the  draughtsman,  make  changes  in  his  picture  (a  few  trifles  ex- 
cepted). To  secure  beauties  in  his  picture,  they  must  be  present  in 
the  original.  It  is  therefore  his  object  to  beautifully  pose  and  light 
his  model,  and  in  short  to  arrange  a  living  picture.  Not  until  this 
has  been  done  is  the  mechanical  process  put  into  operation.  It  is  by 
no  means  true  that  only  beautiful  originals  will  furnish  artistically 
perfect  pictures.  Every  original  has  its  faults.  The  photographer 
must  reproduce  his  original  from  the  point  where  it  shows  the  least 
faults,  or  he  must  cover  them  by  artifices.  If  he  fails  in  this,  the  very 
best  of  chemicals,  apparatus,  and  formulae,  will  fail  to  produce  an 
artistically  beautiful  picture. 


ON  LIGHT  AND  ILLUMINATION. 


Light  is  the  element  of  life,  the  drawing-pencil  of  the  photogra- 
pher. It  is  the  brush  with  which  he  paints.  For  him  a  thorough 
knowledge  of  this  element  is  as  important  as  it  is  for  the  painter  to 
possess  an  exact  knowledge  of  his  colors. 

The  physical  principles  of  illumination  we  have  already  explained 
in  the  second  part.  We  would  refer  to  these,  that  a  judgment  may 
be  formed  of  the  strength  of  light  under  different  circumstances.  Here 
we  have  it  with  the  sesthetic  principles  of  illumination.  In  the  former 
chapter  we  have  made  the  presupposition  that,  with  the  drawing  arts, 
it  is  possible  to  obtain  a  true  picture  of  nature.  We  must  here  make 
another  restriction.  In  fact,  not  a  single  ^picture  is  true  ;  it  only  ap- 
pears so.  The  artist  who  paints  a  sunset  scene,  paints  the  sun,  per- 
haps, with  vermilion  and  white.  These  colors  have  not  near  the 
brilliancy  of  the  setting  sun,  which  is  at  least  a  hundred  thousand  times 
lighter,  nevertheless  such  a  true  colored  sunset  makes  a  fabulous  true 
impression.  The  cause  lies  here  in  the  effect  of  contrast.  A  gray 
paper  appears  dark  on  a  white  ground  ;  on  a  black,  however,  light, 
much  lighter  than  it  really  is ;  for  this  reason,  the  red  sun  appears 
lighter  through  contrast  with  the  heavily  shaded  objects.  These 
effects  of  contrast  also  help  in  photography.  An  under-exposed  pic- 
ture, when  printed  plain,  produces  a  chalky-white  face;  in  like  manner, 
washed  goods,  aside  of  a  deep  black  coat.  If  the  coat  is  covered  with 
india-ink,  so  that  it  will  print  gray,  the  face  will  not  appear  so  white. 
In  photography,  we  have  as  the  lighter  white,  the  paper ;  the  deepest 
black,  the  dark  surface  of  albumen  colored  by  light.  Between  both 
extremes,  we  must  keep  the  choice  of  the  tones,  which  shall  appear  in 
the  finished  picture  ;  the  richer  these  gradations  of  tone  are,  the  pleas- 
anter  our  eye  is  impressed.  Conditions  are  that,  what  appears  lighter 
in  nature,  must  also  appear  in  the  picture  lighter ;  the  darker,  also 
darker  in  the  picture.  The  numberless  delicate  tone  gradations  of 
nature  are  in  this  case  for  the  educated  eye  the  only  guide  ;  they  can- 
not be  produced  absolutely  true,  but  very  nearly  so. 


ON  LIGHT  AND  ILLUMINATION. 


301 


Like  the  painter  or  draughtsman  the  photographer  has  for  his  pur- 
pose the  production  of  a  picture  on  a  plane  surface  which  shall  give 
the  beholder  the  impression  of  a  reality.  The  figures  must  not  appear 
flat  like  the  paper  which  bears  them,  but  plastic,  with  foreground, 
middle,  and  background. 

There  are  two  ways  of  producing  this  apparent  solidity.  The  first 
of  them  is  by  means  of  perspective. 

All  objects  of  equal  size  appear  smaller  in  nature  when  seen  at  a 
distance ;  the  draughtsman,  bearing  this  in  mind,  decreases  the  pro- 
portions of  his  figures  with  the  distance.  He  succeeds  thus  in  pro- 
ducing the  impression  that  the  objects  are  both  near  and  distant, 
although  all  the  figures  in  his  picture  are  equidistant  from  our  eyes. 
Pictures,  in  which  these  laws  of  perspective  have  been  neglected,  for 
instance,  old  pictures  of  Van  Eyck,  Kranach,  etc.,  appear  flat.  Hence 
arises  the  importance  of  a  knowledge  of  perspective  both  to  the  painter 
and  draughtsman. 

The  second  method  of  giving  a  plastic  appearance  to  flat  objects  is 
the  proper  distribution  of  light  and  shade. 

We  draw  two  right-angled  triangles  alongside  each  other,  and  both 
will  appear  as  flat  figures.  As  soon,  however,  as  we  shade  the  one 
with  india-ink,  so  that  the  shadow  will  gently  decrease  from  the  side 
towards  the  centre,  the  triangle,  although  always  remaining  a  plane, 
will  appear  like  a  cone,  and  on  the  other  hand  round  objects  will  often 
appear  flat  when  these  contrasts  of  light  and  shade  are  wanting. 

The  principal  method  of  making  plastic  pictures  is,  therefore,  by 
the  proper  employment  of  contrasts,  and  the  artist  has  them  in  his 
power,  but  he  must  know  how  to  use  them.  We  will  now  proceed  to 
the  special  consideration  of  these  contrasts. 

Let  us  consider  first  the  raw  material  with  which  we  paint, — the 
light     This  ink,  in  its  original  purity,  is  so  powerful  that  we  cannot 
wr  t  with  it  in  our  studios  when  we  wish  to  produce  real  half-tones. 
|g  n  direct  sunlight  we  will  get  a  portrait  glaring  white  on  one  side, 
and  sharply  defined,  not  gently  shaded,  and  black  on  the  other. 

Even  when  the  sunlight  does  not  strike  the  model  directly,  the  re- 
flections from  windows  and  other  objects  would  become  a  source  of 
great  annoyance.  Even  curtains  afford  only  a  partial  protection 
against  this  direct  sunlight.  A  considerable  portion  of  it  penetrates, 
destroys  the  shadows,  and  makes  the  picture  weak.  For  this  purpose 
we  not  only  exclude  the  direct  sunlight  from  the  model,  but  also  from 
the  atelier  itself,  by  making  the  latter  face  towards  the  north.  We 
go  further  and  construct  sunshades,  working  only  with  the  diffused 
light  of  the  clear  or  clouded  sky. 


302 


THE  PRACTICE  OF  PHOTOGRAPHY. 


While,  generally  speaking,  the  rays  of  sunlight  may  be  considered 
as  being  parallel,  those  which  emanate  from  the  sky  take  all  possible 
directions;  horizontal  when  they  come  from  the  horizon,  vertical 
when  they  come  from  the  zenith.  These  circumstances  are  important. 
While  in  consequence  of  the  parallelism  of  the  sun's  rays,  a  body  on 
which  the  sun  shines  will  show  sharply  defined  contrasts  of  light  and 
shade,  a  body  illuminated  by  diffused  light  will  show  these  contrasts 
obliterated.  This  is  the  reason  why,  under  such  circumstances,  full 
and  round  bodies  appear  flat,  as  can  easily  be'observed  by  looking  at 
an  intricate  building  on  a  dull  day.  It  is  no  wonder  that  photographs 
taken  on  such  a  day  always  have  a  flat  appearance. 

The  portrait  of  a  person  would  have  an  equally  flat  appearance  if 
it  received  light  from  all  sides  of  the  atelier.  This  shows  the  necessity 
of  employing  a  one-sided  light  when  we  wish  to  produce  plastic 
pictures. 

To  make  such  pictures  we  supply  our  glass-houses  with  curtains, 
which  we  can  raise  or  lower  at  pleasure.  Such  a  one-sided  light  gives 
a  living  variation  of  light  and  shade.  It  does  not  follow,  however,  by 
any  means,  that  the  shaded  side  of  a  picture  should  not  receive  any 
light  at  all.  On  the  contrary,  it  must  be  slightly  illuminated,  so  that 
by  chemical  action  too  strong  contrasts  may  be  modified,  that  the 
details  may  become  visible,  and  that  there  may  be  a  gentle  transition 
from  light  to  shadow.  In  which  direction  then  must  the  principal 
mass  of  light  strike  the  person? 

Different  cases  are  possible.  The  light  may  strike  the  person  from 
the  front,  i.  e.,  coming  from  the  direction  towards  which  the  point  of 
the  nose  is  directed  ;  or  sideways,  i.  e.,  horizontally  at  right  angles  to 
the  previous  direction  ;  and  finally  from  above,  or  in  the  direction  of 
the  longest  axis  of  the  body.  We  have  to  discriminate,  therefore, 
between  front-light,  top-light,  and  side-light.  Let  us  supposl  now 
that  the  glazed  side  of  the  atelier  is  hung  with  curtains,  and  t'ne.a 
small  slit  is  opened  at  the  side  of  the  person.  If  the  person  itself 
stands  with  its  front  at  right  angles  to  the  glazed  side,  it  is  evident 
that  it  will  be  struck  by  the  side-light.  Turning  now  the  chest  and 
the  head  towards  this  light,  it  will  be  changed  on  the  person  to  front- 
light.  This  shows  that  the  direction  of  the  light  required  depends  on 
the  position  of  the  person,  and  it  becomes  necessary  to  define  the  ex- 
pressions top-light,  side-light,  and  front-light,  in  order  not  to  be  mis- 
understood ;  and  as  I  shall  in  future  frequently  use  these  terms  I  will 
give  the  following  explanation  (see  Fig.  97)  : 

Suppose  the  paper  be  the  floor  of  the  atelier,  and  the  square  A  the 
photographic  apparatus,  P  the  person.    The  direction  of  the  head 


ON  LIGHT  AND  ILLUMINATION. 


303 


and  chest  is  a  matter  of  indifference.  We  call  the  light  which  strikes 
the  person  in  the  direction  of  the  line  V  V  (the  connecting  line  with 
the  apparatus)  front-light;  the  light  which  is  horizontal  at  right 
angles  to  this,  in  the  direction  of  S  S,  we  call  side-light ;  the  vertical 
light  from  above  the  top-light. 


Besides  these  three  principal  directions  the  light  can  strike  the 
person  in  other  directions,  for  instance  obliquely  in  the  direction  of 
the  line  L  L,  as  front  side-light,  or  obliquely  from  above,  as  front 
top-light,  etc.,  expressions  which  are  easily  understood.  It  is  now  my 
object  to  describe  the  effect  of  these  principal  directions  of  light. 
I  give  four  photographs,  one  of  which,  T,  has  been  taken  with  top- 
light  only,  the  other,  S,  with  direct  side-light,  and  the  third,  F,  with 
front-light,  the  fourth,  T  S  F,  with  a  front  top  side-light.    With  the 


T. 


aid  of  these  pictures  we  will  see  what  a  powerful  effect  the  direction 
of  the  light  has  on  the  relief,  the  color  of  the  picture,  the  resemblance 
of  the  features,  and  the  whole  character  of  the  physiognomy. 

I  consider  it  necessai^  to  remark  that  the  four  pictures  are  por- 
traits of  the  same  individual,  that  they  were  taken  immediately  one 


304 


THE  PRACTICE  OF  PHOTOGRAPHY. 


after  the  other,  and  excepting  the  light,  under  circumstances  as  nearly 
identical  as  possible.  I  make  this  remark  because  the  surprising  dif- 
ference which  these  four  pictures  exhibit — only  in  consequence  of  the 
different  illumination — has  caused  many  who  have  seen  them  to  ex- 
press doubts  that  they  really  were  pictures  of  the  same  person. 


Now  let  us  first  consider  the  effect  of  the  different  lights  on  the  re- 
lief of  the  face. 

We  notice  in  T  that  the  eyes  are  deeply  sunk  in  their  sockets,  the 
nose  is  projecting,  and  casts  a  long  shadow ;  the  forehead  is  white 
and  glaring,  whereas  the  chin  appears  dusky ;  there  is  no  division  from 
the  neck,  and  the  mouth  is  imperfect ;  the  ears  appear  dark,  because 
they  are  shaded  by  the  hair;  the  coat  and  background  show  almost 
the  same  color. 

In  8  the  face  appears  as  symmetrically  parted  in  two  halves,  one 
light  and  one  dark.  The  chin,  which  in  T,  nearly  runs  together 
with  the  neck  as  a  gray  flat  mass,  is  shown  quite  distinct  and  vigorous 
in  8,  and  shows  a  dimple  above  the  upper  lip.  Two  sharp  wrinkles 
make  their  appearance,  which  are  invisible  in  T.  In  like  manner  a 
wrinkle  can  be  discerned  aside  of  the  nose.  The  dull  eye  in  T  as- 
sumes a  pleasanter  look  in  8.  The  coat  stands  out  visibly  from  the 
background  by  its  different  colors,  which  is  not  the  case  in  T. 

F  is  like  a  box  seen  from  the  flat  side ;  the  sockets  of  the  eyes  are 
scarcely  indicated.  Of  the  characteristics  which  in  Tand  8  are  to  be 
seen,  not  a  trace  is  left.  The  characteristic  projecting  chin  in  Tand 
8,  appears  flat  in  F;  the  eyes  are  gray ;  the  nose  is  gently  lost  in  the 
eyebrows,  and  forms  with  these  two  symmetrical  nooks.  The  whole 
is  like  a  board  on  which  the  main  outlines  rave  been  drawn.  This 
shows  that  with  the  aid  of  illumination  we  ccn  obliterate  wrinkles  and 
cavities  in  the  face,  or  can  make  them  appear  nore  prominent. 


F. 


T.  S.  F. 


ON  LIGHT   AND  ILLUMINATION. 


305 


When  we  consider  the  effect  of  the  illumination  on  the  color  of  the 
different  parts,  we  will  notice  at  once  the  great  difference  in  the  color 
of  the  hair.  They  appear  gray  in  the  photographs  T  and  8,  where 
the  light  falls  on  them  (the  most  so  in  T),  while  in  F  the  color  is 
more  black. 

In  T  we  recognize  each  individual  hair,  and  also  on  the  light  side 
of  8,  while  in  F  the  hair  forms  a  homogeneous  black  spot,  with  very 
little  detail. 

The  cause  of  this  want  of  detail  is  the  equal  illumination  which 
every  hair  receives  from  the  front,  so  that  we  can  only  see  the  light 
side.  It  is  quite  different  with  side-light,  where  we  see  on  every  hair 
its  bright  and  its  shaded  side,  and  thus  each  hair  becomes  distinct 
from  the  other.  The  hair  in  F  appears  much  darker.  The  reason  of 
this  is  that  the  model  was  much  further  removed  from  the  light  when 
the  picture  was  taken.  This  is  also  the  reason  why  the  coat  appears 
much  darker,  and  the  background  much  lighter  than  in  8  and  T, 
simply  because  it  received  as  much  light  as  the  sitter  (except  where 
the  background  is  shaded  by  the  person),  while  in  Tand  8  the  back- 
ground stands  a  few  feet  back  of  the  light  opening,  and  receives  only 
that  part  of  the  light  which  either  vertically  or  horizontally  strikes 
the  person. 

The  bright  color  of  the  coat  on  the  illuminated  side  in  T  (the  coat 
of  the  sitter  was  black)  must  be  noticed.  This  demonstrates  that  with 
the  aid  of  illumination  we  can  modify  to  a  considerable  degree  the  color 
of  hair,  background,  and  clothing. 

The  next  point  to  be  considered  is  the  effect  of  illumination  on  the 
character  of  the  picture ;  and  the  most  superficial  observer  must 
admit  that  a  great  many,  who  believe  that  a  clean  and  neatly  exe- 
cuted picture  must  always  be  a  good  likeness,  are  grossly  in  error. 

The  eyes  in  T  look  dark  and  weeping,  and  this  sinister  expression 
is  increased  by  the  dark-colored  mouth,  and  the  dark  cheek  and  chin. 
How  harmless  and  even  sleepy  the  picture  in  F  appears.  The  shade- 
less  eyes,  look  fishlike  and  expressionless,  the  lines  which  give  energy 
to  the  face  are  wanting,  and  the  mouth  is  without  expression. 

The  picture  8  is  intermediate  between  the  two.  It  is  not  so  insipid 
as  F,  nor  so  stern  as  T.  The  contrasts  of  light  and  shade  give  a 
lively  expression  to  the  face,  only  the  shaded  side  appears  still  a  little 
too  threatening  when  compared  with  the  light  side.  The  picture  is 
more  characteristic  than  the  other  two,  but  it  does  not  show  us  the 
man  as  he  is  ;  it  is  too  angular,  and  he  looks  too  much  like  a  goat. 
We  see  from  the  qbove  how  the  whole  character  of  a  face  may  be  varied 
considerably  by  illumination.    We  can  make  a  gruff  and  uuhappy- 

20 


306 


THE   PRACTICE  OF  PHOTOGRAPHY. 


looking  face  appear  to  look  cheerful  and  pleasant,  and  we  can  give 
an  energetic  expression  to  a  sleepy-looking  countenance. 

But  my  readers  will  ask,  Which  of  the  three  pictures  shows  the 
true  character  of  the  man  ?  and  I  answer,  None  of  them.  That  every 
one  may  get  an  idea  how  the  man  actually  does  look,  and  form  an 
idea  how  the  three  different  modes  of  illumination  have  changed  the 
expression  of  his  countenance,  I  add  the  portrait  which  his  friends 
consider  a  perfect  likeness,  and  a  true  representation  of  hi§  character 
in  TSF. 

In  this  picture  the  shadows  in  the  hollow  of  the  eye  are  not  as  deep, 
however,  as  in  T,  nor  as  uneven  as  in  S.  Further,  the  wrinkles  on  the 
upper  lip  and  near  the  nose,  which  in  F  are  missing  altogether.  The 
shaded  side  is  not  as  dark  as  in  S.  The  whole  face  receives,  through 
the  gentle  transition  from  light  on  the  one  side  to  the  shaded  on  the 
other,  a  plastic  effect,  leaving  the  relief  forms  of  the  face  stand  out 
nicely  without  exaggeration  (like  the  eyes,  deep,  in  T,  or  the  chin, 
high,  in  S).  From  the  gentle  play  of  light  and  shade  arises  such  a 
gradation  of  tone  as  none  of  the  other  pictures  show.  This  applies  to 
clothing  as  well  as  to  the  hair  and  face.  This  happy  effect  of  illumi- 
nation is  attained  by  a  combination  of  the  three  different  modes  of 
illumination — i.  e.,  top-light,  side-light,  and  front-light,  or  what  is  the 
same  thing,  a  'front  top-light  from  an  oblique  direction.  In  this  case 
the  main  quantity  of  light  which  strikes  the  person  proceeds  from  an 
opening  which  is  a  few  feet  in  front,  above,  and  either  to  the  right  or 
left,  in  such  a  manner  that  the  light  strikes  the  sitter  at  an  angle  of 
about  45°.  In  an  atelier  which  is  hung  with  curtains  as  illustrated 
in  Fig.  98,  such  an  arrangement  of  the  light  is  easily  managed  by  re- 


FlG.  98. 


moving  some  of  the  top  curtains,  L,  L,  and  the  adjoining  side  cur- 
tains, L',  L",  a  few  feet  in  front,  of  the  person,  K.    These  openings, 


ON  LIGHT   AND  ILLUMINATION. 


307 


in  clear  weather,  daring  the  summer,  would  answer  for  an  artistic  il- 
lumination, and  painters,  in  fact,  make  use  of  such.  But  in  photog- 
raphy, the  shadows  so  obtained  are  too  dark,  and  would  produce  an 
effect  like  the  picture  S,  therefore  the  whole  space,  and  with  it  the 
shadows,  must  be  lighted  up  by  opening  the  side-light  curtains,  S,  S, 
and  the  skylight  curtains,  0,  0.  If  a  quick  exposure  is  desired,  the 
curtains  between  S  and  L,  and  between  0  and  L,  are  also  drawn  up. 
The  shaded  side  can  also  be  lit  up  by  a  reflecting  screen. 

The  method  of  illumination  abovementioned  produces  the  rotundity 
and  relief  of  the  model  in  the  richest  manner,  and  painters  make  it 
the  foundation  of  their  shadow  constructions. 

We  find  this  illumination  also  in  most  of  the  pictures  of  our  promi- 
nent portrait  painters,  simply  because  it  appears  to  our  feelings  as 
being  the  most  natural,  aud  there  are  many  photographers  who  will, 
as  if  by  instinct,  place  their  model  in  exactly  that  corner  of  the  atelier 
w7here  this  mode  of  illumination  is  produced  by  local  causes.  Others, 
again,  have  put  up  curtains  and  removed  them  again,  have  changed 
their  glass-houses,  until  finally  their  pictures  assumed  -that  natural 
appearance  which  depends  altogether  on  the  illumination. 

When  we  consider  the  effect  of  such  a  normal  light  on  the  model, 
we  will  find  that  on  the  forehead  (for  instance,  on  the  right),  is  the 
strongest  light,  while  on  the  opposite  side,  on  the  lower  jaw,  we  will 
find  the  deepest  shadows.  There  are  a  number  of  ateliers  where  this 
mode  of  illumination  is  employed  with  every  model,  without  excep- 
tion. 

The  model  is  placed  in  a  spot  from  which  the  side  and  top-light  is 
partially  excluded  by  curtains  and  masonry ;  consequently  he  will  re- 
ceive light  mainly  from  the  side  front.  Curtains  are  thereby  often 
unnecessary  if  the  position  of  the  atelier  has  been  correct  from  the 
beginning.  Otherwise,  a  few  screens  placed  in  proper  position  will 
assist. 

Such  an  arrangement  may  suffice  for  a  great  many  faces,  but  it  can- 
not be  denied  that  by  employing  the  same  mode  of  illumination  in- 
variably, the  pictures  will  become  monotonous. 

In  photographs  this  monotony  is  even  more  objectionable  than  in 
oil  paintings,  as  the  painter  by  the  aid  of  colors  has  the  means  to  pro- 
duce a  great  variety  of  effects.  It  is  quite  different  with  the  photog- 
rapher. In  his  hands  light  and  shade  have  to  replace  the  effects  of 
color.  He  can  replace  variety  only  by  a  skilful  manipulation  of  the 
illumination,  and  the  more  or  less  inclined  angle  under  which  the 
light  strikes  the  object  is  here  of  primary  importance. 


308 


THE  PRACTICE  OF  PHOTOGRAPHY. 


We  have  to  mention  that  a  top-light,  0,  or  a  side-light,  S  (Fig.  98), 
proceeding  from  a  great  distance,  produces  a  similar  effect  to  that  of 
a  front-light.  A  top-light  of  large  dimensions,  immediately  above  the 
sitter,  is  in  its  effects  similar  to  a  side-light,  a  circumstance  which 
must  be  borne  in  mind  in  an  atelier  which  is  wide,  but  compara- 
tively low,  and  vice  versa.  A  very  high  side-light  will  produce  sim- 
ilar effects  to  a  top-light,  as  can  easily  be  noticed  in  any  very  high 
atelier. 

It  follows  that  as  we  increase  or  diminish  the  size  of  the  opening, 
L,  L,  or  as  we  approach  it  or  remove  the  sitter  from  it,  we  can  give 
to  the  light  more  or  less  the  character  of  front-light,  top-light,  or  side- 
light, and  modify  the  character  of  the  model  to  a  considerable  extent. 

Suppose  we  have  a  well-marked,  energetic,  and  expressive  face. 
By  removing  the  sitter  from  the  source  of  light,  we  give  the  character 
of  front-light  to  it,  and  infuse  mildness  and  softness  into  the  harsh 
features. 

And  so  the  other  way,  when  we  have  a  flat,  sleepy,  and  otherwise 
little-marked  face,  we  should  give  to  the  light  more  of  the  character 
of  top-light,  and  the  face  will  get  more  energy  and  life. 

With  certain  small-cheeked  faces,  the  employment  of  side-light  is 
to  be  recommended.  It  lights  up  the  cavities  under  the  cheek-bones 
on  the  light  side,  makes  these  concave  parts  appear  more  rounded 
and  full,  while  the  details  on  the  other  side  are  lost  in  shadow. 

For  ladies  of  a  "  certain  age,"  who  sometimes  become  very  annoy- 
ing to  the  photographer,  the  employment  of  a  gentle  front-light  is  to 
be  recommended.  It  will  light  up  the  wrinkles  and  remove  the  un- 
pleasant shadows. 

Yes,  we  can  place  the  whole  face  in  the  shadow  (which  of  course 
must  not  be  too  dark),  only  throwing  a  few  light-effects  over  the  most 
prominent  parts,  and  still  get  good  effects. 

Generally  speaking,  we  may  lay  down  the  rule  that  we  must  illu- 
minate all  the  elevations  and  depressions  which  we  wish  to  modify,  in 
such  a  manner  that  they  throw  no  shadow,  or  only  a  very  small  one, 
and  vice  versa. 

By  such  tricks  in  illumination,  not  only  the  parts  we  intend  to  re- 
move generally  suffer,  but  also  the  neighboring  ones  which  ought 
to  remain.  Flatness  easily  steps  in,  and  therefore  it  is  now  preferred 
to  modify  deep  shadows  and  wrinkles  by  retouching  the  negative. 
The  most  judicious  and  artistic  illumination  is  that  of  the  picture 
T  8  F,  and  with  this  a  majority  of  cases  can  be  reached.  A  turning 
of  the  head  more  to  the  light,  or  shaded  side,  placing  the  figure  for- 


ON  LIGHT   AND  ILLUMINATION. 


309 


wards  or  backwards,  will  produce  those  variations  easily,  which  are 
stipulated  by  peculiarity  of  the  physiognomy.  Important  here  is  the 
application  of  the  tricks  in  illumination. 

We  can  modify  the  shortcomings  of  the  original,  but  we  must  not 
obliterate  them  altogether,  for  in  that  case  character  and  likeness 
would  be  lost.  How  far  we  may  go  in  this  respect  cannot  be  deter- 
mined by  any  rule,  but  the  thinking  artist  must  be  guided  by  his 
sight  aud  the  gift  of  observation. 

The  observing  artist  will  also  notice  a  slight  difference  in  the  * 
brightness  of  the  hands  and  the  face.    In  every  portrait  the  face  is  of 
paramount  importance.    It  must  receive  the  principal  light,  and  all  the 
other  parts  must  be  kept  subdued  and  subservient  to  it. 

Nothing  can  be  more  repulsive  than  those  pictures  where  the  arms 
and  hands  appear  as  prominent  white  spots,  strongly  contrasting  with 
the  drapery  and  clothing.  The  upper  part  of  the  body  should  be 
kept  lighter  than  the  lower  parts.  With  dark  screens,  which  are  placed 
a  few  feet  from  the  sitter,  and  partially  shade  the  hands  and  feet,  this  is 
easily  accomplished.  Loescher  &  Petsch  use  such  a  shade-screen  with 
great  advantage,  particularly  in  avoiding  over-exposure  of  white 
dresses.  The  screen  is  a  frame  five  feet  wide,  covered  with  dark 
cloth,  and  moves  on  rollers.  The  upper  part  is  movable  around  a 
horizontal  axis,  so  as  to  give  more  or  less  inclination.  It  is  self-evi- 
dent that  the  production  of  such  light-effects  requires  a  skilled  eye, 
which  will  appreciate  the  slightest  gradations  from  light  to  dark. 

For  training  the  eye  in  this  respect,  I  would  recommend  the  pho- 
tographer to  practice  on  plaster  of  Paris  busts.  Such  busts  should 
be  placed  in  the  atelier  on  the  same  spot  where  the  sitters  are  placed. 
All  the  light  should  be  excluded  by  closing  all  the  curtains,  and  now, 
by  admitting  the  light  first  from  one  direction,  then  from  another, 
now  from  above,  and  next  sideways,  the  effect  on  the  face  should  be 
carefully  watched. 

The  variations  are  not  only  surprising,  but  entertaining  and  in- 
structive, and  whoever  will  take  the  trouble  to  photograph  them,  and 
make  a  short  memorandum  of  the  mode  of  illumination,  can  make 
for  himself  an  album  of  studies  that  will  materially  assist  him  in  se- 
lecting the  proper  mode  of  illumination  for  the  living  model.  More 
important  are  studies  from  living  models. 

Here  must  be  observed  the  peculiar  light  effects,  which  occur  when 
the  person  moves  away  in  the  curtained  position,  Fig.  98,  from  Kf 
towards  the  camera ;  the  light  then  comes  in  from  the  back  sideways, 
and  this  paired  with  the  front-light,  coming  from  S  and  0,  produces 


310 


THE  PRACTICE  OF  PHOTOGRAPHY. 


a  very  fine  effect.  This  brings  us  to  the  so-called  Rembrandt  effect, 
in  which  the  whole  face  is  dipped  in  a  half-shadow  on  the  side,  while 
generally  on  the  profile  a  sharp  edge  of  light  is  shown.  These  effects 
are  produced  by  the  annexed  arrangement,  Fig.  99.  Wis  the  open 
side-light,  G  the  person,  A  the  camera,  h  the  background,  r  a  very 

light  reflector.    Moreover,  a  slight  degree 
here  is  only  brought  into  use.  The  person 
inclines  the  face  towards  the  right  (in  the 
£  figure),  so  that  it  appears  in  profile  at  A. 

The  objective  must  be  protected  with  a 
screen  from  the  direct  light  of  the  side- 
Q  light.    In  such  Rembrandt  effects  there 

O  was  and  is  yet  much  accomplished,  or 

sinned.    The  pictures  look  very  effective, 
but,  as  the  illumination  is  an  unusual  one, 
jgr  the  persons  appear  also  unusual,  and  there- 

fore  unlike.  Whoever  has  an  eye  for  light 
effects  can  produce  more  such  tricks,  which 
we  however  would  rather  recommend  for  artists'  pictures  (actors)  than 
for  the  great  public.  Kurtz's  arrangements  for  taking  Rembrandts 
are  shown  herein  further  on.  In  Berlin  the  taste  for  such  pieces  of 
light  effect  has  died  away  rapidly.  They  might  still  draw  at  other 
places.  One  thing  must  not  be  forgotten,  i.  e.,  "  One  rule  will  not  ap- 
ply for  all,"  and  care  should  be  taken  not  to  use  one  and  the  same 
light  effect  for  all  persons,  regardless  of  sex,  age,  or  peculiarities  of 
the  physiognomy. 

All  that  I  have  shown  as  taking  place  on  the  human  face  repeats 
itself  on  all  other  forms.  Just  as  cavities  or  prominences  on  the 
human  head  can  be  obliterated  or  exaggerated  by  the  mode  of  illumi- 
nation, so  also  can  we  modify  the  appearance  of  other  plastic  objects, 
as  buildings,  bas-reliefs,  machinery,  etc. 

It  is  the  rule  to  illuminate  in  such  a  way  that  the  details  ivhich  we  de- 
sire to  show  prominently  in  the  picture  are  by  the  illumination  brought  to 
the  proper  prominence.  Art  objects  make  the  choice  of  illumination 
easy,  in  so  far  as  all  artists  place  their  models  under  a  light  which 
strikes  the  object  at  an  angle  of  45°  obliquely  from  above.  Whether 
the  obliquity  is  from  the  right  or  the  left  side  is  still  a  question,  and 
when  the  artist  himself  does  not  give  the  direction,  experiment  must 
show  from  which  side  the  light  acts  the  most  favorably.  Without 
subjecting  oneself  to  examination  and  criticism,  we  will  never  obtain 
•a  satisfactory  result. 


ON  LIGHT   AND  ILLUMINATION. 


311 


This  oblique  light  with  an  inclination  of  45  degrees  will,  under 
most  circumstances,  be  the  most  suitable. 

Two  more  points  have  to  be  considered, — the  size  of  the  object  and 
the  distance  of  the  source  of  light,  i.  e.,  the  window  of  the  atelier. 
Suppose  we  have  two  pillars,  one  of  large  diameter,  a  (Fig.  100),  and  a 
small  one,  b,  placed  at  equal  distance 

from  a  window.  It  will  be  easily  seen  Fro-  10°- 


that  the  first  will  show  a  different 
illumination  from  the  second.  The 
light  plays  more  around  the  smaller 
pillar  on  the  shady  side  than  on  the 
large  one.  The  shady  side  contracts 
while  the  light  side  expands.  If 
we  wish  to  photograph  the  smaller 
pillar,  under  similar  conditions  of 


light  and  shade,  we  have  to  decrease 

the  light  opening.  This  is  the  reason  why  an  illumination  which  has 
been  arranged  for  a  life-size  model  is  unsuited  for  a  smaller  object. 

The  second  point  is  the  distance  from  the  glass  wall. 

We  have  shown  above  that  the  brilliancy  of  a  point,  which  re- 
ceives the  light  of  the  sky  through  a  window,  decreases  as  the  square 
of  the  distance  from  the  window  increases.  With  a  very  large  window 
opening  this  decrease  is  not  so  strong,  but  still  very  perceptible  when 
we  consider  that  in  such  cases  the  shady  side  of  a  model  is  only 
illuminated  by  the  light  reflected  from  the  back  wall  of  the  atelier. 
It  becomes  evident  that  the  contrast  between  light  and  shade  will  be 
stronger  as  we  approach  the  model  to  the  glass  wall ;  we  have  it  in 
our  power,  therefore,  to  increase  or  decrease  these  contrasts  by  placing 
the  model  in  different  positions. 

It  must  not  be  overlooked  that,  generally  speaking,  contrasts  are 
stronger  in  photographic  pictures  than  they  appear  to  our  eyes.  Very 
often  the  shaded  side,  which  to  our  eye  represents  all  the  details,  ap- 
pears on  the  photograph  as  a  pitch-black  spot.  This  is  most  striking 
with  yellow,  green  or  red  objects,  less  so  with  white  ones,  or  cobalt 
and  ultramarine  blue. 

A  plaster  bust  will  generally,  even  without  artificial  arrangements, 
show  good  details  in  the  shadows,  but  it  is  different  with  human 
beings,  and  still  worse  with  dark-colored  objects,  such  as  iron  and 
bronze.  When  it  is  intended  that  the  shadows  of  such  objects  shall 
not  appear  altogether  black,  we  must  either  introduce  direct  light 
on  the  shadow  side  or  arrange  reflectors  to  throw  the  light  in  that 
direction. 


312  THE  PRACTICE  OF  PHOTOGRAPHY. 

In  an  atelier  with  a  north  front  the  illumination  of  the  shadows  by 
direct  light  is  an  easy  matter.  Generally  the  model  is  handled  as 
we  have  already  described. 

To  the  eye  the  effect  is  visible  on  the  model.  By  increasing  the 
amount  of  front-light  the  time  of  exposure  becomes  relatively  short- 
ened. The  light  and  shade  contrasts  become  more  and  more  decided 
by  approaching  the  model  to  the  glass  side  of  the  house. 

The  illumination  by  reflecting  screens  is  very  generally  employed. 
When  the  atelier  is  small  and  the  rear  wall  light,  the  latter  will  act 
as  a  reflector  (see  effect  of  indirect  light),  and  many  photographers 
will  only  notice  this  fact  when  they  are  suddenly  placed  in  another 
larger  atelier  with  a  dark  rear  wall.  The  floor  of  the  atelier  acts 
similarly  to  a  reflector.  It  lights  the  lower  shadows  of  the  model. 
This  effect  is  also  very  often  overlooked.  Every  object  in  the  atelier, 
provided  it  is  not  absolutely  black,  acts  more  or  less  as  a  reflecting 
screen.  Those  photographers  who  boast  that  they  work  without  re- 
flecting screens  may  make  a  note  of  this. 

We  have  taken  pictures  in  which  a  lady  sat  reading  at  a  table, 
the  head  inclined  over  the  book.  Here  the  whole  face  was  in  the 
shade,  and  this  was  only  lit  up  by  the  book  itself  acting  as  a  reflector. 
Of  course  this  must  be  placed  so  that  the  reflected  effects  can  be  really 
seen.  For  what  cannot  be  seen  with  the  naked  eye  generally  does 
not  appear  in  the  picture.  Just  as  advantageously  we  use  the  white 
dress  of  a  standing  lady  as  a  reflector  for  the  shadow  side  of  her 
sitting  neighbor  in  a  group.  Such  means  dare  only  be  applied  with- 
out being  noticed  in  the  picture.  A  hidden  looking-glass  often  is 
very  serviceable. 

For  a  movable  reflecting  screen  I  would  recommend  a  frame,  E 
(Fig.  101),  which  revolves  around  the  hori- 
zontal axis,  a  b,  and  is  moved  from  place  to 
place  on  rollers.  Others  are  so  arranged  that 
they  can  be  placed  high  or  low.  One  side 
of  the  frame  should  be  covered  with  tin-foil, 
the  other  with  white  paper.  This  secures 
two  surfaces  of  different  reflecting  power. 
The  frame  is  placed  on  the  dark  side  of 
the  model,  and  moved  in  different  directions  until  the  eye  observes 
that  the  shadows  become  lighter. 

To  the  beginner  I  would  recommend  experiments  with  a  plaster 
bust.  The  effectiveness  of  the  screen  increases  the  nearer  we  place 
it  to  the  model  (see  effect  of  direct  light).    As  regards  the  most  suit- 


ON  LIGHT   AND  ILLUMINATION. 


313 


able  position  of  the  reflecting  surface  we  soon  notice  that;  even  with 
a  dull  surface,  such  as  paper,  the  action  is  analogous  to  a  mirror,  i.  e., 
the  angle  of  incidence  is  like  the  angle  of  reflection. 


OF  THE  PERSPECTIVE. 

When  we  look  at  a  cube  (Fig.  102),  the  sides  of  which  being  of 
equal  length,  we  will  find  that  they  appear  to  our  eye  of  very  differ- 
ent length.  The  surface  fronting  our  eye  appears  as  a  square ;  the 
others  become  shortened  in  a  remarkable  manner.  The  surfaces  ap- 
pear quite  irregular ;  the  parallel  lines  converge  towards  the  point  o. 
Similar  appearances  we  notice  on  all 
other  bodies.   The  human  arm  hang-  Fig.  102. 

ing  down  along  the  side  of  the  body, 
or  the  pillar,  S,  standing  upright, 
appear  of  full  length,  while  the  arm 
stretched  towards  us,  or  a  pillar  lying 
in  a  horizontal  position,  L,  appear 
"  foreshortened."    The  parts  appear 
contracted,  and  finally  we  see,  in- 
stead of  the  shaft  of  the  pillar,  only 
the  circular  base,  b,  which  either  ap- 
pears circular  when  we  face  it  directly,  or  as  an  ellipse  (which  it  is  not 
in  fact),  and  the  parallel  sides  of  the  pillar  converge  to  a  point.  The 
reason  why  we  do  not  notice  this  falsehood  (for  such  it  is)  is  simply 
because  we  are  used  to  it. 

We  know  from  experience  that  the  arm  pointing  towards  us  only 
appears  short,  and  that  it  is  longer  than  it  appears  to  us.  We  know 
also  that  the  apparently  converging  railroad  tracks  run  actually  par- 
allel. We  constantly  correct,  by  our  experience,  the  appearances  of 
our  vision.  A  child  without  experience  will  try  to  seize  the  moon. 
It  is  the  duty  of  the  painter  and  the  photographer  to  represent  the 
foreshortening  correctly,  i.  e.,  as  they  appear  to  our  eyes ;  and  when 
this  is  not  done  the  picture  will  be  untrue. 

The  perspective  teaches  us  the  laws  of  foreshortening.  Our  eye  is 
a  camera  obscura  with  a  simple  landscape  lens.  We  know  from 
optics  that  the  image  of  a  point  lies  on  the  straight  ray  which  is  drawn 
from  the  point  through  the  centre  of  the  objective.  Where  this  line, 
which  is  called  the  principal  ray,  cuts  the  plane  of  the  picture  (the 
ground-glass  in  the  camera  or  the  retina  in  the  eye),  we  will  find  the 
picture  of  the  point  in  question.    The  image  of  a  straight  line  is 


314 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Fig.  103. 


where  the  rays  which  proceed  from  the  different  points  of  the  line, 
after  passing  through  the  centre  of  the  lens,  inter- 
sect the  ground-glass.  These  lines  form  a  plane  in 
the  optical  centre.  This  plane  cuts  the  plane  of  the 
ground-glass  in  a  straight  line.  The  image  of  a 
straight  line  is,  therefore,  in  our  eye  a  straight  line, 
and  the  image  of  a  plane  triangle  is  a  plane  triangle. 
When  the  plane  figure  on  the  retina,  or  the  ground- 
glass,  is  parallel  to  the  object,  then,  according  to 
well-known  stereometrical  laws,  the  image  will  ap- 
pear similar  to  the  original  figure.  Suppose  that  a 
plate  of  glass  has  been  placed  in  front  of  the  eye 
vertical  to  its  axis.  Then  the  rays  which  proceed 
from  an  object,  abed,  will  intersect  the  plate  in 
the  figure  a'  V  c' d'  (Fig.  103).  When  we  construct 
such  a  figure  for  a  given  point  of  intersection  and  a 
given  plane,  then  the  drawing,  when  it  is  brought  to 
the  correct  position  and  distance  in  front  of  the  eye, 
will  give  exactly  such  an  image  as  the  objects  themselves.  This  ex- 
plains the  deception  that  a  correctly  constructed  plane  picture  ap- 
pears in  relief.  A  picture  drawn  in  the  above-described  manner  we 
call  a  perspective  drawing.  It  is  self-evident  that  we  must  look  at  it 
under  the  same  conditions  under  which  it  was  drawn. 

Suppose  that  A  B  CD,  Fig.  104,  is  the  ground  plan  of  a  house,  B 

the  ground-glass,  0  the  focus  of  the 
rays,  abed  the  image  of  A  B  C  D ; 
then  it  is  necessary  that  I  should  place 
my  eye  at  0  in  order  to  see  the  per- 
spective picture,  abed,  exactly  as  the 
object  itself. 

When  I  move  the  ground-glass  closer 
to  the  eye,  for  instance  to  B' ,  it  is  easy 
to  see  that  the  rays  must  cross  each 
other  in  the  eye  under  an  entirely 
different  angle  from  those  which  pro- 
ceed from  A  B  C  D;  and  they  cannot  produce  a  correct  impression. 
The  same  would  take  place  if  I  should  remove  the  picture-plate  away 
from  the  eye  (for  instance  to  B").  Hence  it  follows  that  every  per- 
spective drawing  should  be  looked  at  from  the  standpoint  from  which 
it  was  taken  in  order  to  produce  a  correct  impression. 

A  photograph  is  a  perspective  drawing  where  the  point  of  sight  lies 
in  the  object-lens ;  and  hence  the  eye  must  be  placed  at  the  same  dis- 


ON  LIGHT   AND  ILLUMINATION. 


315 


tance  as  the  object-glass  (i.  e.,  its  focus).  When  this  is  not  done  the 
impression  is  untrue. 

There  are,  however,  lenses  of  four  inches  focus  and  less ;  at  so  short 
a  distance  it  is  impossible  for  the  naked  eye  to  see  a  drawing,  or  any- 
thing else.  Generally  we  look  at  them  at  a  distance  of  at  least  eight 
inches,  and  the  consequence  is  that  the  photograph  produces  an  un- 


natural impression.  This  is  very  often  the  case  with  pictures  taken 
with  wide-angle  lenses. 

When  we  look  at  these  from  too  great  a  distance,  0'  f  (Fig.  105), 
we  will  notice  the  too  great  expansion  of  the  marginal  parts.  The 
foreground  and  the  sides  appear  disproportionately  large.  When  they 
are  placed  at  the  correct  distance,  Of,  which  is  equal  to  the  focus  of 
the  lens,  then  the  angle  of  vision,  C  A  0,  of  the  too  wide  marginal 
parts,  A  C,  B  D,  will  shrink  considerably,  as  they  will  be  seen  con- 
siderably foreshortened  (see  above),  and  the  picture  will  make  a  cor- 
rect impression. 

These  errors  do  not  show  themselves  in  so  striking  a  manner  with 
pictures  that  have  been  taken  with  lenses  of  a  smaller  field  of  vision. 
When,  for  instance,  the  angle  is  equal  to  60°,  it  does  not  make  much 
difference  whether  we  look  at  the  picture  from  the  single  or  double 
focal  length,  as  a  glance  at  the  small  marginal  piece,  A  g,  of  a  field 
of  vision  of  60°,  will  demonstrate.  This  is  the  reason  why  we  do  not 
notice  the  false  perspective,  so  common  in  portraits  which  have  been 
taken  with  lenses  of  a  short  focus,  as  the  field  of  vision  of  these  lenses 
is  less  than  60°.  But  other  abnormities  will  manifest  themselves 
which  we  must  not  overlook. 

When  we  take  from  the  point  P  (Fig.  106),  the  picture  of  a  pillar, 
the  ground  section  of  which  is,  A  B  C  D,  the  lens  to  have  a  focus  of 
seven  inches,  we  obtain  a  picture  in  which  the  sides  A  B  and  C  D 
are  visible.    When  we  substitute,  however,  a  lens  of  three  and  a  half 


Fig.  105. 


ft;  a 


o. 


316 


THE  PRACTICE  OF  PHOTOGRAPHY. 


inches  focus  we  would  have  to  approach  the  object  in  order  to  obtain 
a  picture  of  the  same  size  as  with  the  seven-inch  lens.  For  instance, 
from  the  point  0',  the  sides  A  B  and  CD  are  no  longer  visible;  the 
whole  character  of  the  picture  becomes  changed.  When  we  substi- 
tute a  human  face  for  the  pillar  it  is  evident  that,  with  the  lens  near 
to  the  object,  the  cheeks  will  contract  and  appear  too  narrow  in  pro- 
portion to  the  length  of  the  face. 


The  correctness  of  this  conclusion  the  following  two  illustrations 
will  demonstrate  (Fig.  107).  They  represent  two  pictures  of  the  bust 
of  Apollo.  The  bust  was  placed  exactly  vertical,  the  camera  likewise, 
and  the  direction  of  the  line  of  vision  carefully  adjusted.  The  picture, 
No.  I,  was  taken  with  a  small  patent  Dallmeyer  lens,  at  a  distance  of 
47  inches ;  the  picture,  No.  II,  was  taken  with  a  Steinheil  Aplanatic 
lens,  at  a  distance  of  112  inches. 

The  difference  is  striking.  In  No.  I  the  figure  appears  slender,  the 
chest  is  almost  feeble,  while  the  same  model  yields  in  No.  II  a  full- 
faced,  robust  figure.  That  this  slenderness  does  not  depend  on  an 
illusion  a  measurement  of  distances  will  best  illustrate.  The  distances 
between  the  eye  and  the  point  marked  on  the  chest  with  a  cross  are 
exactly  alike.  The  greatest  expansion  of  the  chest,  however,  includ- 
ing the  stumps  of  the  arms,  amounts  in  No.  I  to  56  millimetres,  and 
in  No.  II  to  59  millimetres.  Looking  aside  from  this  dissimilarity, 
the  character  of  the  two  faces  will  reveal  to  the  attentive  observer 
other  striking  differences.  A  line,  a,  a,  applied  to  the  hair  of  the 
figure  will  run  horizontal  in  No.  II,  while  in  No.  I  it  inclines  to  the 
left  of  the  figure.  The  pedestal,  P,  differs  likewise.  In  I,  the  rings 
are  strongly  inclined  ellipses,  while  in  II  they  are  quite  flat.  The 
stump  of  the  arm,  A,  A,  shows  hardly  any  surface  in  I,  while  in  II  it 
becomes  quite  prominent.  The  support  of  the  back  extends  in  No.  II, 
at  ut  further  to  the  right.  The  head  is  in  II  more  between  the 
shoulders  (see  the  angle  of  the  neck  at  W),  and  the  whole  figure 
seems  to  elevate  the  head  more  in  No.  I  than  in  No.  II.  In  II  the 
head  seems  almost  to  incline  forward,  and  yet  the  figure  was  immova- 


FiG.  106. 


P 


ON  LIGHT  AND  ILLUMINATION. 


317 


ble,  the  lenses  were  free  from  distortion,  the  direction  and  height  was 
in  both  identical ;  nothing  was  different  but  the  distance. 

Besides  the  two  pictures  above  described,  two  others  were  made 
under  exactly  similar  circumstances  at  a  distauce  of  sixty  and  eighty 
inches,  and  when  we  place  the  four  heads  alongside  of  each  other,  we 
notice  that  with  increasing  distance  the  figures  appear  stouter  and  more 


Fig.  107. 

II.  I. 


robust,  the  head  line  inclines  more  and  more,  the  ellipses  of  the  pedes- 
tal become  flatter,  the  chest  increases  in  breadth,  and  the  stumps  of 
the  arms  become  more  prominent.  These  differences  will  show  them- 
selves when  we  take  the  same  head  with  the  same  lens  and  only  change 
the  distance  from  the  object. 

The  author  took  the  Apollo  head  with  a  Dallmeyer  stereoscope 
lens  at  distances  of  five  and  ten  feet.  The  latter  picture  is  of  course 
only  half  the  size  of  the  former.  Differences  were  not  visible  to  the 
naked  eye  on  account  of  the  smallness  of  the  pictures,  but  they  became 
quite  evident  by  magnifying  them,  and  showed  the  same  differences  as 
shown  above  in  the  illustrations. 


318 


THE  PRACTICE  OF  PHOTOGRAPHY. 


We  thus  see  how  different  distances  yield  different  pictures  of  the 
same  object,  exactly  as  a  different  direction  of  the  light  will  give  a 
different  character  to  a  portrait  of  the  same  person. 

Some  will  say  that  all  this  is  trifling,  and  that  it  does  not  make 
much  difference  whether  the  Apollo  is  a  little  stouter  or  a  little  more 
sleuder.  So  far  as  the  Apollo  is  concerned  this  may  be  a  matter  of 
indifference  (most  people  do  not  know  how  the  Apollo  looks  at  all)  ; 
but  the  case  is  quite  different  in  portrait  photography,  and  where  the 
customer's  own  dear  self  is  concerned.  For  their  own  physiognomy 
even  inartistic  people  have  an  exceedingly  keen  eye.  The  most  tri- 
fling things — a  line,  a  wrinkle,  a  curl — is  criticized,  and  differences, 
which  are  not  noticed  in  the  Apollo,  are  easily  observed  in  the  coun- 
terfeit presentment  of  themselves. 

It  is  the  duty  of  the  photographer  to  pay  attention  to  distance. 

To  the  photographer  who  only  works  mechanically  this  may  be  an 
inconvenience ;  but  the  intelligent  and  ambitious  artist  will  know 
how  to  take  advantage  of  it.  He  will  not  make  a  thin  person  appear 
still  thinner  by  taking  a  photograph  at  a  short  distance,  nor  will  he 
increase  the  circumference  of  a  stout  one  by  placing  a  considerable 
distance  between  the  camera  and  the  model.  This  is  particularly  the 
case  with  bust  pictures,  but  still  more  so  with  large  heads,  where 
on  the  one  hand  the  distances  are  short,  and  where  on  the  other  hand 
the  breadth  of  the  body  is  almost  equal  to  the  height  of  the  figure  (so 
far  as  the  same  is  visible  in  the  picture). 

With  standing  figures,  where  the  breadth  is  comparatively  small 
in  proportion  to  the  length,  these  errors  caused  by  distance  are  not  so 
apparent. 

Perhaps  many  will  wish  to  know  which  distance  is  the  proper  one, 
and  which  gives  the  most  correct  picture. 

This  depends  upon  the  individual,  I  might  say,  and  refer  to  the 
example  of  the  stout  and  slender  person,  which  I  gave  above,  and 
where  entirely  different  distances  are  proper.  Generally  speaking, 
painters  recommend,  for  making  a  drawing,  a  distance  which  is  at 
least  twice  as  great  as  the  height  of  the  object.  For  a  person  five  feet 
high,  the  distance  would  be  ten  feet;  for  a  bust  (half  the  length  of 
the  body),  a  distance  of  about  five  feet. 

The  painter,  however,  has  greater  freedom.  He  can  add,  or  leave 
off,  or  change,  just  as  he  chooses.  His  guide  is  his  artistic  feeling.  I 
think  that  the  photographer  needs  this  feeling  also.  The  opticians 
have  furnished  him  with  different  lenses)  that  he  may  make  pictures 
of  the  same  object  and  of  the  same  size  from  different  distances.  A 


ON  LIGHT   AND  ILLUMINATION. 


319 


portrait  photographer  should  be  provided  with  lenses  of  different  focal 
length.^ 

Everything  is  proper  when  employed  in  the  right  place.  And  thus 
the  question  is  answered:  Which  portrait  apparatus  furnishes  the 
most  correct  picture,  particularly  when  the  negative  has  to  serve  for 
enlargement  ? 

The  preceding  chapter  will  demonstrate  that  even  a  correct  drawing 
lens  will  give  different  pictures  at  different  distances.  I  obtain  a  dif- 
ferent result  when  I  take  a  picture  at  five  or  ten  feet  distance.  With 
small-sized  pictures,  these  differences  are  not  very  striking ;  but  when 
we  enlarge  to  life  size,  they  become  very  noticeable,  and  every  one 
will  observe  them. 

Let  us  suppose  that  the  original  is  five  feet  high,  then  it  will  re- 
quire, according  to  the  above  academical  rule,  a  distance  of  ten  feet 
to  give  a  proper  standpoint  for  the  contemplation  of  the  same.  But 
in  order  that  the  picture  should  make  a  correct  impression  at  this 
distance,  it  is  necessary  that  the  negative  be  taken  at  the  same  dis- 
tance, no  matter  with  what  objective,  provided  it  draws  correctly  and 
defines  sharply.  If  it  has  been  taken  at  a  shorter  distance,  the  life- 
size  picture  will  appear,  under  the  given  propositions,  untrue. 

These  circumstances  are  modified  by  the  nature  of  the  object. 

Let  us  take  as  an  object  an  artistically  sculptured  chalice.  In 
drinking  out  of  it  or  in  looking  at  it  we  take  it  in  our  hands  and  place 
it  at  a  distance  of  about  two  feet  from  our  eyes.  We  will  get  a  true 
picture  of  such  an  object  only  by  making  a  photograph  at  such  a 
short  distance,  and  the  truth  of  this  assertion  becomes  quite  evident 
when  we  magnify  a  picture  which  has  been  taken  at  a  greater  distance. 
The  untruth  of  the  latter  becomes  evident  at  once  by  comparing  the 
picture  with  the  original,  particularly  when  the  width  of  the  latter  is 
large* in  comparison  to  its  height. 

Cavities  are  different  from  prominences. 

When  A  B,  C  D  (Fig.  108),  is  the  interior  of  a  box,  we  will  see  the 
side  A  B  from  P  much  more  foreshortened  than  from  0'  or  N.  If, 
therefore,  a  picture  is  taken  under  like  circumstances  from  near  or 
far,  it  will,  appear  in  the  former  case  broader  in  proportion  to  the 


*  For  large  heads  of  carte  de  visite  size,  which  are  now  in  so  much  demand, 
he  should  have  three  numbers  of  sufficient  light  (a  point  of  great  importance) 
at  his  command : 

1  portrait  head  of  about  24  lines  and  4  inches  focus  at  about  5  feet  distance. 
1  ti  u  30       it       7  a  it  7  « 

1         "  *  36       "     12  "  "        11  " 

In  most  cases  the  second  one  will  be  sufficient. 


320  THE  PRACTICE  OF  PHOTOGRAPHY. 

height.  This  relation  becomes  evident  in  taking  a  perspective  street 
view.    At  a  short  distance,  with  a  wide-angled  instrument,  the  nearer 

Fig.  108. 


! 

  r 

| 

o'   

parts  will  appear  unusually  broad.  The  same  will  happen  when  we 
suppose  that  A  C  represents  the  body  and  C  D  the  lap  or  the  feet  of 
a  sitting  person.  The  lap  will  appear  much  broader  in  proportion  to 
the  body.  It  would  be  the  same  if  C  D  represented  the  feet  of  a 
person  facing  the  camera.  They  would  appear  larger  from  N. 
Finally,  let  us  imagine  that  C  D  represents  the  carpet  or  the  floor  of 
a  room  ;  it  would  appear  broader  or  with  a  steeper  ascent  from  N. 
When  we  take  a  picture  of  one  and  the  same  person  from  two  dif- 
ferent standpoints,  P  and  N,  with  two  lenses  of  different  focal  lengths, 
in  such  a  manner  that  the  height  of  the  body  shall  remain  the  same 
in  both  pictures,  we  will  find  in  the  pictures  taken  at  a  short  distance 
that  the  projecting  parts  (hands,  feet,  lap,  etc.)  are  too  wide,  while 
the  receding  ones,  as  the  cheeks,  are  too  small ;  the  floor  and  chair 
ascend  too  much  (Fig.  109).  For  comparison,  look  at  the  picture, 
Fig.  110,  which  has  been  taken  from  a  greater  distance.    When  we 


Fig.  109.  Fig.  110. 


suppose  that  A  B  (Fig.  108)  is  the  ground-plan  of  a  house  or  a  win- 
dow, then  it  will  appear  broader  when  taken  from  O'  than  if  taken 
from  P. 


ON  LIGHT  AND  ILLUMINATION. 

This  is  the  reason  why  windows  and  doors  ap- 
pear too  broad  when  taken  at  a  short  distance  with 
a  lens  of  a  wide  field  of  view,  and  hence  look  com- 
pressed, as  will  be  noticed  in  many  pictures  taken 
with  a  pantoscope  apparatus.  This  is  also  the 
reason  why  the  distance  of  the  apparatus  and  the 
size  of  the  field  of  vision  are  of  so  much  importance 
in  giving  a  true  picture  of  an  object.  How,  under 
these  circumstances,  and  even  with  a  perfectly  cor- 
rect perspective,  quite  abnormal  figures  are  pro- 
duced, the  annexed  picture  of  balls  will  demonstrate. 
Balls  will  always  appear  round  to  us,  or  circular ; 
but  when  they  are  located  at  the  margin  of  the 
field  of  vision — i.  e.,  w7hen  the  rays  intersect  the 
plane  of  the  picture  under  a  very  oblique  angle, 
then  the  perspective  figure,  even  when  mathematic- 
ally correct,  will  be  an  ellipse. 

Such  a  figure  we  will  not  consider  a  true  one,  as 
our  eye  has  been  accustomed  to  seeing  a  ball  under 
any  circumstances  as  a  circle,  and  we  cannot  blame 
the  painter  when  he  ignores  the  rules  of  perspective 
and  draws  them  always  as  circles.  Unfortunately 
the  photographer  cannot  do  the  same ;  he  must  re- 
produce the  figure  which  the  lens,  constructed  ac- 
cording to  mathematical  principles,  furnishes. 

Distortions  similar  to  those  described  on  the 
balls  will  always  manifest  themselves  with  lenses  of 
comparatively  small  fields  of  vision.  The  balls 
B  and  D  are  on  the  margin  of  a  field  of  only  about 
35°.  The  balls  A  and  E  are  at  the  edge  of  a  field 
of  64^°.  The  former  angle  is  nothing  unusual 
with  portraits,  particularly  with  groups.  The  latter 
is  frequently  employed  in  landscape  and  architec- 
tural photography.  The  marginal  figures  will  easily 
appear  too  thick  when  taken  at  a  short  distance 
with  a  wide  field  of  view.  Look  at  the  two  figures 
(Fig.  116,  Fig.  117) ;  they  are  the  marginal  figures 
of  the  same  bas-relief ;  the  one  taken  at  a  distance 
of  3|  feet,  the  other  at  8|  feet.  The  head  in  Fig. 
117  appears  twisted,  thick,  and  the  left  foot  turned 
outwards,  while  Fig.  116  is  more  correct. 

In  taking  groups  a  long  distance  should  be 
chosen,  and  stout  persons  should  not  be  placed  at 

21 


322  THE  PRACTICE  OF  PHOTOGRAPHY. 

the  margin,  but  in  the  centre,  and  we  should  only  employ  a  large 
field  of  vision  when  circumstances  admit  of  no  other. 

That  a  too  large  field  of  view  in  landscape  photography  produces 
a  too  broad  foreground,  has  already  been  mentioned  (see  above). 

This  is  apt  to  disturb,  especially  when  the  main  object  of  the  pic- 
ture lies  in  the  distance,  which  appears  aside  of  the  large  foreground 
small  and  cramped.  The  large  field  of  view  leads  also  to  singular 
changes  of  shape  in  the  figure  of  a  landscape.  As  proof  we  annex 
two  pictures  of  the  same  mountain  view  of  the  Carpathian  Range, 
which  we  made  with  a  pantoscope  and  a  Steinheil.  Fig.  113  repre- 
sents the  right  side  of  the  Steinheil ;  Fig.  112  the  right  side  of  the 


Fig.  112. 


pantoscope  picture.  The  total  difference  of  the  mountain  outline 
appears  to  the  eye  at  once.  A  superficial  resemblance  is  here  ;  this 
concerns  only  the  grouping  of  the  mountains  and  their  general  form. 
In  both  figures,  a  is  the  highest  mountain;  b  is,  however,  in  Fig.  113, 


Fig.  113. 


the  second  highest,  in  Fig.  112  the  lowest  of  all.  The  pointed  moun- 
tain at  the  right  appears  broader  in  Fig.  112  than  in  Fig.  113.  If 
both  pictures  are  now  carefully  compared  with  nature,  it  will  be 
found  that  the  Steinheil  comes  nearest  to  it ;  it  gives  the  outline  of  the 


ON  LIGHT   AND  ILLUMINATION. 


323 


mountains  more  correctly.  The  pantpscope,  however,  makes  a  better 
total  impression,  which  is  not  in  the  optical,  but  clearly  to  the  land- 
scaping relations.  Such  deviations  are  shown  much  oftener  than  is 
thought ;  they  have  been  so  far  overlooked.  That  they  occur  lies 
simply  in  the  nature  of  the  perspective,  according  to  which  our  in- 
struments delineate,  and  in  this  will  be  found  its  solution.  A  similar 
distortion  occurs  here  as  with  the  five  balls  (Fig.  114).  What  is 
said  of  a  sphere  will  also  apply  to  a  hemisphere.  Imagine  in  front 
of  the  camera  a  row  of  hemispherical-formed  mountain-tops;  these 
will  suffer  the  same  distortion,  on  the  edge  of*  the  field  of  view,  as  the 
balls ;  they  will  be  broader.  If  the  balls  are  not  in  a  row,  but  in  a 
semicircle,  i.  e.,  the  balls  on  the  side  nearer  to  the  camera  than  the 
middle  ones,  the  broadening  will  be  worse.  Something  similar  occurs 
in  nature,  when,  for  instance,  the  mountains  form  a  mountain  hollow, 
it  will  appear  the  more  striking  the  larger  the  field  of  view.  The 
one  picture  (Fig:  113),  is  cut  out  of  the  side  of  a  plate,  the  field  of 
view  being  60°.  The  point  of  sight  was  under  the  highest  summit. 
This  summit  was  nearest  to  the  edge,  and  suffered  therefore  the  dis- 
tortion ;  it  extends  still  higher.  This  extension  is  explained  by  imag- 
ining the  five  balls  in  a  perpendicular  position  (Fig.  114). 

The  other  picture  is  from  a  plate,  with  a  field  of  view  of  90° ;  the 
point  of  sight  was  towards  the  left  below  the  second  highest  mountain 


Fig.  114. 


b  (Fig.  112),  therefore  the  parts  lying  to  the  right  in  the  former 
moved,  in  the  latter,  more  to  the  edge ;  they  were  analogous  to  the 
balls  A  and  C  on  account  of  the  broadening  caused  by  the  large 
angle  of  vision,  and  more  striking  than  in  the  first  picture,  in  which  it 


324 


THE  PRACTICE  OF  PHOTOGRAPHY. 


was  scarcely  possible.  Now  the  heightening  of  single  mountains  is 
yet  to  be  explained.  Three  balls  placed  in  a  row,  the  camera  in  this 
case  imagined  very  broad  placed  parallel  in  front  of  them,  produces 
a  picture  which  of  course  shows  a  broadening  of  the  balls  at  the 
edges,  but  no  degree  of  heightening.    All  pictures  have  in  a  per- 


Fig.  115. 


pendicular  position  the  same  diameter,  as  shown  in  Fig.  111.  If, 
however,  the  balls  lie  oblique  to  the  camera,  as  in  the  annexed  cut, 
Fig.  115,  the  picture  will  be  different.  The  three  balls,  which  in  the 
first  parallel  position  of  the  camera  appeared  of  the  same  height,  but 
different  breadths,  appear  now,  not  only  of  different  breadths,  but  also 
different  heights,  i.  e.,  the  ball  at  the  edge  c  higher  than  b,  and  this 
higher  than  a  (Fig.  115).  For  this  reason  the  mountains  grow  in 
height  and  breadth,  on  the  edge  of  a  landscape  if  the  camera  is 
placed  in  a  similar  position ;  thus,  this  singular  fact  finds  its  solution 
in  the  simple  laws  of  perspective. 

The  artist  who  paints  a  landscape  cannot,  according  to  this,  strictly 
conform  to  the  laws  of  central  perspective ;  he  corrects  the  construc- 
tion which  the  perspective  produces  with  the  impression  made  on  his 
eye  by  nature.  The  question  now  is,  if  such  failures  can  be  photo- 
graphically avoided.  The  answer  is,  yes,  but  only  partly,  i.  e.,  by  the 
aid  of  a  camera  having  a  ground-glass  which  can  be  placed  in  an 
oblique  position.  We  mean,  however,  such  a  one  which  moves  on  a 
perpendicular  axis.  Imagine  the  ground-glass,  Fig.  114,  without 
changing  the  position  of  the  camera,  turned  so  as  to  be  more  parallel 
to  the  balls ;  for  instance,  in  the  position  of  the  dotted  line,  the  failure 
for  the  right-hand  side  will  be  less  marked.  For  the  other  side  it  is 
of  course  reversed  ;  here  the  distortion  by  the  turning  of  the  ground- 
glass  will  be  worse,  because  the  ground-glass  is  placed  in  a  more 
oblique  position  to  the  (dotted)  ball  on  the  left.  Very  often,  how- 
ever, the  characteristic  objects  of  a  landscape  are  on  one  side  of  the 
picture,  the  other  side  being  of  an  inferior  nature ;  a  little  distortion 
*  in  this  case  is  of  little  consequence.  The  inclination  of  the  ground- 
glass  can  be  done  to  correct  the  other  side  very  advantageously. 

Still  another  point  is  the  height  of  the  apparatus  and  its  direction. 

The  normal  position  of  the  apparatus  is  the  horizontal  one.  In 
that  position  the  eye-point — i.  e.,  the  point  where  the  continuation  of 


ON   LIGHT   AND  ILLUMINATION. 


325 


the  axis  of  vision  would  intersect  the  plane  of  the  picture — would 
fall  in  a  line  exactly  in  the  horizon — i.  e.,  in  the  line  where,  on  a  large 
sheet  of  water,  the  water  and  the  sky  appear  to  meet. 


This  normal  position,  however,  is  maintained  by  photographers 
only  in  taking  architectural  views.  When  it  is  neglected,  in  such 
cases  the  vertical  lines  of  the  buildings  will  not  appear  vertical,  but 
inclined — i.  e.,  converging  at  the  top  when  the  apparatus  is  turned 
upwards,  and  converging  at  the  bottom  when  the  apparatus  is  turned 
downwards.* 

Such  pictures  look  very  ugly.  With  portraits  and  simple  land- 
scapes we  very  often  deviate  from  this  horizontal  position.  The  eye- 
point  must  be  looked  for  either  in  the  ground  or  in  the  sky.  In  this 
case  we  will  see  in  the  former  instance  more  of  the  ground,  and  in 
the  latter  more  of  the  sky.  Under  some  circumstances  this  may  be 
an  advantage.  In  rows  of  trees,  where  we  wish  to  avoid  an  excessive 
foreground  in  order  to  get  an  insight  into  the  splendid  mass  of  foliage, 
we  must  direct  the  apparatus  upwards. 


*  The  explanation  is  easy.  The  rays  proceeding  from  a  straight  line  will 
form  a  plane  at  the  point  of  crossing,  and  this  will  intersect  the  plane  of  the 
ground-glass  in  a  straight  line.  When  we  imagine  a  succession  of  lines 
parallel  to  the  ground-glass,  the  planes  of  rays  proceeding  from  them  will 
intersect  the  ground-glass  in  parallel  lines  according  to  well-known  geo- 
metrical laws  When,  however,  the  ground-glass  is  inclined,  the  intersecting 
lines  will  converge. 


Fig.  116. 


Fig.  117. 


326 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Bedford  has  done  this.  That  the  stems  of  the  trees  converged  did 
not  matter  much.  What  influence  the  inclination  of  the  apparatus 
exerts  in  portrait  photography  is  shown  most  strikingly  by  taking  the 
picture  of  a  bust  with  an  apparatus  pointing  upwards,  and  then  from 
the  same  standpoint  with  the  camera  pointing  downwards,  as  the 
annexed  figure  (118)  shows.  In  the  third  figure  the  head  appears  to 
incline  forward,  like  that  of  an  old  man  ;  in  the  first  the  person  stands 
perpendicular,  like  a  soldier;  while  in  the  second  instance  the  head  is 
thrown  backwards  and  the  eyes  are  turned  heavenward. 

In  this,  one  thing  must  also  be  borne  in  mind;  the  head  is  like  a  ball. 
If  it  is  in  the  centre  of  the  field  of  view  it  will  be  normal  as  the 
middle  ball  (p.  321);  if  above  or  below  it  is  extended  in  its  position 
of  length,  the  same  as  the  upper  and  lowest  of  the  five  balls  if  placed 
in  a  perpendicular  position.  A  face  can,  therefore,  be  made  slimmer 
by  moving  it  out  of  the  centre  of  the  field  of  view;  a  quick  eye  can 
detect  this  already  on  the  ground-glass.  Focus  a  short-focussed  lens 
horizontally  on  a  head,  so  that  it  will  be  in  the  centre  of  the  ground- 
glass.  Then  tilt  it  forward,  so  that  the  head  is  a  little  above  the 
centre,  it  will  be  seen  instantly  that  it  becomes  slimmer.  In  stand- 
ing figures  the  head  cannot  be  kept  in  the  centre  very  well  if  the 
picture  shall  be  sharp  from  head  to  foot.  The  objective  should  not 
be  placed  lower  than  the  breast.  The  lens  will  see  the  head  from 
below ;  the  aspect  secured  can  readily  be  seen  in  Fig.  II  in  the  Apollo, 
which  was  taken  with  a  camera  pointing  up.  It  shows  more  of  the 
chin,  the  nostrils  can  be  looked  into,  the  hair  is  shortened.  To  obviate 
this  in  standing  pictures,  let  the  person  (by  standing  the  apparatus 
low)  incline  the  head  slightly.  In  like  manner,  the  failure  shown  in 
Fig.  Ill,  which  occurs  when  the  apparatus  is  placed  high,  can  be 
avoided  by  placing  the  face  of  the  subject  a  little  higher. 

The  effect  becomes  still  more  striking  with  antique  statues.  Gen- 
erally they  are  calculated  and  executed  for  a  high  standpoint.  They 
must  be  copied  with  a  camera  turned  upwards,  while  with  reclining 
figures  (Endymion,  Cleopatra,  or  Queen  Louisa)  the  apparatus  should 
be  turned  downwards. 

The  elevation  of  the  apparatus  above  ground  is  of  still  more  im- 
portance. Many  mistakes  are  made  in  this  respect.  The  normal 
height  is  the  height  of  the  eyes  above  ground,  which  for  a  standing 
figure  is  about  four  and  three-quarters  feet.  When  the  apparatus  is 
placed  higher,  we  will  see  the  objects  from  above  (bird's  eye  view)  ; 
when  we  go  lower,  we  will  see  the  objects  in  what  is  called  a  frog  per- 
spective. For  a  sitting  figure,  we  may  assume  the  observer  to  be  in  a 
sitting  posture — i.  e.,  the  eye  or  the  camera  at  a  height  of  about  four 


328 


THE  PRACTICE  OF  PHOTOGRAPHY. 


feet.  For  a  sitting  person  the  apparatus  is  generally  placed  on  a 
level  with  the  head  of  the  model  and  inclined  forward,  while  for  a 
standing  person  the  height  of  the  chest  and  the  horizontal  position  is 
adopted.  In  the  former  case  we  can  elevate  the  head  of  the  model ; 
in  the  second  case  we  can  depress  it  to  equalize  errors. 

When  the  apparatus  is  placed  too  high  the  person  will  appear  more 
in  a  bird's  eye  perspective,  and  we  see  a  larger  part  of  the  top  of  the 
head.  The  eyes  appear  depressed,  the  throat  is  covered  by  the  chin, 
etc.  When  the  apparatus  is  placed  too  low  the  reverse  takes  place. 
We  look  into  the  nostrils  and  the  sockets  of  the  eyes ;  we  look  under 
the  chin,  and  the  forehead  becomes  foreshortened. 

In  landscape  photography  the  height  of  the  apparatus  is  still  more 
important.  In  order  to  gain  a  proper  standpoint  we  have  to  ascend 
buildings  and  climb  mountains. 

We  must  observe  that  all  the  parallel  horizontal  lines  which  are 
not  parallel  to  the  ground-glass  will  converge  towards  a  point  in  the 
horizon — the  point  of  disappearance  or  vanishing-point.  . 

As  the  horizon  is  located  in  the  height  of  the  eye — i.  e.,  the  camera 
— it  follows  that  the  ground  will  ascend  more  and  more  as  we  raise 


Fig.  119. 


the  horizon.  See  Fig.  120,  where  the  eye-point  is  taken  at  the  normal 
height  of  a  human  figure,  the  next  at  the  height  of  the  hips  (Fig.  119), 
and  the  third  at  twice  the  height  of  a  human  figure  (Fig.  121).  In 
the  first  picture,  where  the  horizon  is  lowest,  the  lines  of  the  street 
ascend  gently;  the  upper  parts  of  the  window,  however,  form  strongly 
inclined,  or,  as  they  are  called,  tumbling  lines ;  the  lines  of  the  step 
incline,  and  the  milestone  reaches  to  the  clouds.  When  we  ascend 
the  steps  (Fig.  119),  the  ground  lines  ascend  more,  and  the  window 


ON   LIGHT  AND  ILLUMINATION. 


329 


lines  are  more  horizontal.  From  such  a  standpoint  the  lower  objects 
appear  in  a  bird's-eye  perspective;  persons  and  trees  become  foreshort- 
ened and  appear  small  and  compressed ;  it  does  not  create  a  natural 


Fig.  120. 

1 


impression  to  see  the  ground  ascend  over  objects  which  we  are  used  to 
seeing  prominently  above  ground,  or  to  see  the  lines  of  window  sills, 
which  generally  run  in  a  descending  direction,  become  ascending. 


Fig.  121. 


Such  a  high  standpoint  in  taking  a  street  view  is  only  to  be  recom- 
mended when  it  offers  other  great  advantages. 

Here  is  still  another  point.    In  a  perspective  view,  the  lines  of  the 


330 


THE  PRACTICE  OP  PHOTOGRAPHY. 


cornices  of  a  building  will  appear  to  tumble  when  viewed  from  a  nor- 
mal standpoint — i.  e.,  the  height  of  the  eye  of  a  standing  person ; 
more  and  more  so  the  higher  the  building  is.  We  are  accustomed  to 
calculate  the  height  of  a  building  from  the  degree  of  inclination  of 
the  upper  lines.  This  is  the  reason  why  buildings  taken  from  a  high 
standpoint,  where  these  lines  approach  to  the  horizontal,  appear  low 
and  depressed,  and  fail  to  make  a  great  impression. 

Paul  Veronese,  who  painted  a  splendid  hall,  knew  this  effect  very 
well.  He  gave  to  the  upper  lines  a  strong  inclination,  and  placed 
the  eye-point  intentionally  lower  for  them  than  for  the  floor,  in  order 
to  make  them  steeper. 

He  has  offended  the  learned  mathematicians,  but  gained  in  artistic 
effect.  It  is  not  intended  that  a  picture  should  solve  a  mathematical 
problem  or  conform  to  it. 

In  narrow  streets  the  selection  of  the  proper  standpoint  is  often  so 
difficult  that  in  spite  of  all  our  good  intentions  we  must  be  satisfied 
with  something  very  imperfect.* 

ARRANGEMENT. 

We  very  often  hear  in  ordinary  life  the  commonplace  remark, 
"  artistic  confusion,"  and  many  draw  the  conclusion  that  every  chaotic 
mixture  of  objects  must  be  artistic.  We  will  not  investigate  here  how 
many  photographers  hold  this  view.  I  have  known  one  who  in  order 
to  heighten  the  effect  of  his  landscape  dragged  all  possible  things  into 
it.  Piles  of  wood  were  carted  to  the  place,  stones  were  thrown  in  the 
foreground,  the  wheelbarrow  on  which  the  apparatus  had  been  moved 
had  to  do  duty,  and  when  nothing  else  was  to  be  had,  the  ground  in 
front  was  dug  up  in  order  to  make  the  view  "picturesque."  He  did 
still  worse  with  his  portraits ;  clocks,  picture  frames,  vases,  chairs,  bot- 
tles, and  footstools  were  so  piled  together,  that  finally  it  became  dif- 
ficult to  find  the  person  amongst  the  heap  of  rubbish. 

It  requires  an  advanced  artistic  education  to  understand  that  dis- 
order and  picturesque  are  ideas  by  no  means  identical.    It  is  not 


*  I  hare  seen  views  of  the  staircase  in  the  Museum  in  Berlin  which  were 
taken  with  wide-angled  lenses.  In  these  the  joists  of  the  ceil i rig  are  taken 
from  below  (frog  perspective),  while  the  statues  on  the  groundfloor  are  taken 
from  a  bird's  eye  view  ;  however,  the  public  is  satisfied  ;  all  they  want  is  to 
have  a  picture  with  a  great  many  objects  in  it ;  how"  they  look  does  not  matter. 
From  this  desire  to  see  a  great  deal  at  once  originated  probably  the  mania  for 
ascending  mountains.  Every  one  is  delighted  with  the  view  from  the 
Brocken  (Harz  Mountains),  although  it  is  bare  of  all  beauty ;  but  we  see  a 
great  deal  at  once,  although  very  little  that  is  beautiful. 


ARRANGEMENT. 


331 


artistic  when  the  objects  in  the  picture  are  arranged  with  a  stiff  sym- 
metry and  mathematical  precision  ;  as,  for  instance,  the  sacred  pic- 
tures of  the  oldest  schools  of  painting ;  in  the  centre,  we  find  the  holy 
virgin,  to  the  right  and  left  each  six  apostles  drawn  up  like  soldiers 
of  the  line,  and  not  only  symmetrical  in  position,  but  also  in  the  car- 
riage of  the  hands,  feet,  and  head ;  the  left  side  of  the  picture  the 


Fig.  122. 


Lessing,  after  Eietschel, 


exact  counterpart  of  the  right.  Art  demands  liberty  and  order,  and  this 
shows  itself  in  an  easy  symmetrical  arrangement.  Man  himself  is  a 
symmetrical  figure ;  we  can  divide  him  into  two  parts,  and  the  one 


332 


THE  PRACTICE  OF  PHOTOGRAPHY. 


part  would  be  the  exact  copy  of  the  other ;  for  example,  a  soldier 
making  "  front  face,"  the  legs  together,  the  hands  drawn  close  to  the 
body,  the  head  directed  vertically  forward. 

A  person  will  only  take  such  a  position  when  forced  to  do  so,  and  it 
will  lack  beauty  because  it  is  unnatural.  Let  us  contemplate  a  man 
standing  in  an  easy  position  (Fig.  122) ;  he  will  very  seldom  rest  on  both 
legs,  like  a  soldier,  but  generally  rests  on  one,  the  supporting  leg,  while 
the  other  is  left  free.  Neither  do  both  arms  hang  down,  but  he  places 
them  in  different  positions,  and  generally  the  head  and  body  are 
turned  in  different  directions ;  and  hence  it  is  that  he  appears,  even  in 
the  lifeless  picture  itself,  capable  of  motion,  while  the  symmetrical 
soldier  appears  even  in  life  stiff  and  rigid,  and  still  more  so  in  the 
picture. 

What  is  applicable  for  a  standing  figure,  will  be  true  also  for  a 
sitting  one.  Here  also  a  strong  symmetrical  sitting  person  appears 
ugly.  The  position  is  pleasanter  if  the  head  has  a  different  position 
than  the  body  (see  Fig.  123),  the  feet  different  again  from  the  rump, 
and  arms,  hands,  and  coat  collar  a  little  different  position  on  each 
side,  the  head  a  little  inclined.  As  much  as  stiff  symmetry  displeases, 
the  more  unpleasant  we  perceive  a  wholly  striking  unsymmetry  like 


Fig.  123. 


Fig.  126,  where  the  right  side  is  empty,  while  the  left,  at  all  events, 
shows  a  superfluous  table.  Here  that  is  missing  which  art  scholars 
call  the  artistic  equilibrium.    In  this  condition  of  equilibrium,  it  cor- 


ARRANGEMENT. 


333 


responds  to  a  line  b,  Fig  124,  falling  towards  the  right,  on  the  other 
side  one  falling  towards  the  left.  Notice,  for  instance,  the  arm 
outlines  of  the  sitting  figure,  123,  the  seam  of  the  coat  in  Lessing, 
Fig.  122.  If  the  picture  consists  of  all  oblique  parallel  lines  (Fig. 
125),  this  equilibrium  is  not  fulfilled,  and  this  want  is  felt  by  the 
observer,  although  he  is  innocent  as  to  the  cause  of  it.  See  the  pic- 
ture (Fig.  126). 


Fig.  124.  Fig.  125. 


In  the  picture  (Fig.  126),  for  which,  and  three  others,  we  are  in- 
debted to  Mr.  Robinson's  excellent  work,  "Pictorial  Effect  in  Photog- 
raphy," a  great  many  of  the  main  lines  run  in  the  same  direction. 
The  legs  of  the  figure,  the  chair  legs,  upper  arm,  coat  collar,  and  the 
back  of  the  chair,  and  not  a  single  line  which  runs  in  a  symmetrically 


Fig. 126. 


opposite  direction ;  to  the  right  we  have  an  empty  space,  while  to  the 
left  a  vase  and  a  table  crowd  the  space  and  withdraw  the  eye  from 
the  main  object.  That  the  monotonous  and  unnecessarily  parallel 
lines  could  have  been  easily  avoided  it  is  not  hard  to  understand;  but 
we  must  not  think  that  we  must  avoid  absolutely  all  parallel  lines  in 
a  picture ;  we  must  leave  what  is  an  organic  necessity,  but  we  must 


334 


THE  PRACTICE  OF  PHOTOGRAPHY. 


not  unnecessarily  increase  them,  as  the  author  has  done  in  the  pre- 
ceding picture,  by  letting  both  arms,  both  legs,  the  legs  and  the  back 
of  the  chair  run  in  the  same  direction. 

In  conclusion,  I  will  give  a  sketch  in  profile,  after  Paton  (Fig.  128). 
The  balance  has  been  beautifully  maintained ;  the  folds  of  the  dress, 
which  fall  towards  the  left,  find  their  symmetrical  opposite  in  the  lines 
of  the  arms,  which  descend  towards  the  right.  The  shrubbery  at  the 
right  fiuds  its  opposite  in  the  two  trees  on  the  left ;  a  few  objects  in 
the  foreground  on  the  right  side  correspond  with  the  figure  and  give 
it  an  easy  appearance.  The  few  branches  and  the  hat  in  the  imme- 
diate foreground  are  not  without  meaning.  They  form,  so  to  speak, 
the  continuation  of  the  lines  of  the  arms,  which  incline  to  the  right. 
When  we'  cover  the  former  by  a  piece  of  paper,  the  figure  will  at 
once  lose  its  importance.  If  the  child  should  stretch  its  invisible 
foot  towards  the  right,  the  accessories  will  no  longer  be  necessary. 

Photographers  have,  of  course,  more  trouble  to  produce  such  free 
symmetrical  arrangement  than  the  artist,  for  the  stiffness  of  the  per- 
sons sitting  is  often  the  greatest  resistance  to  their  endeavors.  But 


Fig.  127. 


often  it  is  not  the  fault  of  the  model,  but  lack  of  taste  and  artistic 
posing  of  the  photographer.  We  annex  as  a  frightful  example  a 
picture  of  a  dressed-up  Turkish  lady  in  Berlin,  Fig.  127.    At  a  dis- 


ARRANGEMENT. 


335 


tance  it  seems  as  though  the  figure  was  sitting  with  legs  spread  apart ; 
on  closer  examination  it  will  be  seen  that  towards  the  left  there  is  no 
leg  but  a  drapery,  no  doubt  placed  there  to  fill  up  the  empty  space. 
This  want  of  taste  condemns  itself.  The  figure  is  made  to  look  more 
horrible  by  the  kinked  (paper?)  breeches,  and  the  placed-up  leg,  which 
can  hardly  be  recognized  as  such,  which  besides  cuts  off  the  essential 
parts  (the  waist  and  elbow)  of  the  plump  posed  upper  part  of  the  body. 
The  artist  is  licensed,  for  producing  the  artistic  equilibrium,  to  resort 
to  draperies  and  requisites  as  his  aids.  The  less  he  needs  such  aids 
the  better  for  him,  for  they  are  horrible.  When  they  serve  as  the 
balance  for  essential  parts  of  the  figure,  as  in  Fig,  127,  the  left  leg  is 
balanced.  Side  objects,  like  draperies,  etc.,  must  not  have  the  same 
artistic  claim  in  a  picture  as  the  essential  object.  The  essential  ob- 
ject in  a  portrait xis  only  the  figure  itself. 

A  piece  of  drapery  thrown  over  the  back  of  the  chair  of  Fig.  126, 
and  falling  towards  the  right,  would  establish  the  artistic  equilibrium, 
a  trick  which  is  cheap  and  very  much  liked.  However,  it  would  not 
remove  the  parallel  arm  and  legs,  but  would  only  fill  the  empty  space. 
The  less  an  artist  stands  in  need  of  these  things  the  better  he  is  off. 
That  they  are  not  absolutely  necessary  is  demonstrated  by  the  por- 
trait (Fig.  123),  which  is  copied  from  a  picture  by  the  world-renowned 
C.  V.  Jagemann  in  Vienna.  The  woodcut  does  not  do  justice  to  the 
original. 

Fig.  128. 


It  shows  symmetrical  arrangement  with  full  liberty  of  motion,  and 
yet  without  resorting  to  draperies  or  accessories.  In  every  arrange- 
ment one  thing  should  be  observed, — the  arrangement  must  be  free 


336 


THE  PRACTICE  OF  PHOTOGRAPHY. 


and  unrestrained.  As  soon  as  we  notice  in  a  picture  that  the  artist 
has  carefully  pulled  the  clothing  into  the  proper  folds,  that  he  has 
dragged  furniture  and  draperies  to  his  assistance  in  order  to  establish 
an  equilibrium  of  lines,  when  we  feel  that  the  limbs  and  the  material 
are  forcibly  squeezed  into  a  position  which  they  would  never  assume 
naturally,  then  the  arrangement  appears  artificial  and  inartistic. 

The  portrait  (Fig.  123),  as  well  as  the  sketch  by  Paton  (Fig.  128), 
show  figures  which  rest  on  the  broadest  basis ;  forms  which  narrow 
towards  the  top,  like  a  pyramid.  f 

This  pyramidal  arrangement  we  find  in  numberless  works  of  art. 
Why  does  this  arrangement  harmonize  the  best  with  our  feelings  ? 
It  is  because  the  pyramid  rests  on  the  firmest  foundation  ;  and  we 
demand  a  firm  stand  for  every  figure  at  any  price,  particularly  in 
photography. 

This  is  a  point  which  requires  particular  attention  with  standing  per- 
sons ;  they  are  not  so  easily  brought  within  the  pyramidal  arrange- 


Fig.  129. 


Group  by  Bendemann. 

ment,  and  hence  are  easily  in  danger  of  appearing  in  the  picture  as  if 
they  rested  on  an  insecure  basis. 

We  not  only  find  this  arrangement  on  the  basis  of  the  pyramid  for 
single  persons  in  the  works  of  art,  but  to  a  much  larger  extent  for 
groups. 

I  will  give  as  an  illustration  a  group  by  Bendemann. 


ARRANGEMENT. 


337 


We  see  the  pyramidal  arrangement  not  only  in  the  whole  group, 
but  the  large  pyramid  resolves  itself  into  several  smaller  ones  ;  for 
instance,  to  the  right  the  mother  with  the  child  ;  in  the  centre  the  boy 
with  the  jug,  and  where  the  stream  of  water  accommodates  itself  to 
the  pyramidal  arrangement  the  lines  of  the  right  are  the  opposite  of 
those  of  the  left.  The  boy  playing  the  flute  comes  under  the  same 
arrangement.  We  see  here  that  two  things  of  secondary  importance 
serve  to  complete  the  pyramidal  structure,  but  the  less  we  rely  upon 
or  resort  to  such  artificial  means  the  better  it  is.  Such  accessories  be- 
come perfectly  horrible  when  they  crown  the  pyramid.  I  have  seen 
a  picture  of  two  sitting  persons  where  the  pyramid  was  formed  by 
placing  behind  them  a  step-ladder.  In  fact  two  persons  are  apt  to 
give  the  photographer  much  trouble  in  the  arrangement,  and  even 
the  sculptor  has  great  difficulties  in  properly  disposing  of  such  subjects. 
As  examples  I  would  mention  the  Schiller-Goethe  Group  of  Riets.chel 
and  the  Luther-Melanchthon  Group  by  Schadow.  How  easily  two 
or  three  persons  accommodate  this  pyramidal  arrangement,  is  shown 
in  the  following  instance,  Mieris  and  his  wife  at  breakfast  (Fig.  132), 
a  musical  entertainment  by  Terburg  (p.  343),  a  loving  couple  by 
Metzu  (p.  345). 

Fig.  130. 


Leonardo's  Last  Supper. 

The  difficulty  is  still  greater  when  a  great  number  of  persons  has 
to  be  grouped  together.  This  much  is  to  be  observed,  the  pyramidal 
grouping  must  appear  easy  and  without  stiffness;  it  must  under  no 

22 


338 


THE   PRACTICE  OF  PHOTOGRAPHY. 


circumstances  appear  as  if  made  after  a  stencil  pattern,  in  which 
every  object  is  forced  into  a  given  form. 

There  are  objects  which  are  absolutely  antagonistic  to  the  pyrami- 
dal form.  As  an  example  we  give  "The  Last  Supper,"  by  Leonardo 
da  Vinci. 

It  would  hardly  be  possible  to  arrange  the  thirteen  persons  who  sat 
at  the  table  in  pyramidal  groups.  A  horizontal  arrangement  is  un- 
avoidable unless  we  foreshorten  the  table.  The  nature  of  the  case  de- 
mands it.  The  picture  shows  how  the  artist  disposes  of  a  number  of 
persons,  and  brings  them  all  prominently  into  view.  He  proceeds 
like  the  naturalist.  The  latter,  in  order  to  make  it  comprehensible, 
divides  a  number  of  objects  in  genera  and  families,  or  smaller  groups. 
In  a  similar  manner  the  artist  divides  his  persons  into  two  principal 
groups, — six  apostles  to  the  right,  six  to  the  left ;  each  of  these  two 


Fig.  131. 


Thorwaldsen's  Night. 


groups  is  again  divided  into  two  parts  containing  three  persons  each. 
But  all  the  parts  stand  in  a  harmonious  combination;  they  all  arrange 
themselves  in  accordance  with  the  idea  of  the  picture.  The  arrange- 
ment obeys  the  laws  of  symmetry  in  the  most  perfect  and  easy  manner. 


ARRANGEMENT. 


339 


There  are  works  of  art  in  which  pyramidal  composition  was  possible, 
but  where  it  has  been  purposely  neglected.  Thorwaldsen's  splendid 
Bas-relief,  Night,  is  an  illustration.  With  two  sleeping  children 
(Sleep  and  Death)  the  female  figure  floats  down  to  the  earth ;  around 
her  forehead  is  a  wreath  of  poppy,  indicating  sleep.  We  would  have 
to  force  our  judgment  to  find  a  pyramidal  arrangement  in  this  work 
of  art.  It  would,  in  this  instance,  not  only  be  superfluous,  but  it 
would  also  be  without  motive,  for  the  figure  does  not  demand  stability 
(which  is  a  characteristic  of  the  pyramidal  style),  because  it  is  not  at 
rest;  it  floats  in  the  air. 

When  the  photographer  has  to  group  a  greater  number  of  persons 
he  can  easily  combine  the  horizontal  and  pyramidal  arrangements. 


Fig.  132. 


Mieris  and  his  Wife. 


He  divides  the  numbers,  as  in  Leonardo's  picture,  into  several  smaller 
groups  (which,  however,  must  not  be  disconnected),  and  tries,  in  each 
of  the  smaller  groups,  to  do  justice  to  the  pyramidal  arrangement. 
It  will  be  difficult  for  him  to  create  a  work  of  art  in  this  way.  People 
are  too  unwieldy  and  too  awkward,  but  he  will  succeed  in  making  a 


340 


THE   PRACTICE   OF  PHOTOGRAPHY. 


more  pleasing  group  than  if  he  placed  all  his  figures  stiffly  side  by 
side. 

Often  he  can  combine  a  number  of  persons  by  an  action,  be  it  play- 
ing at  cards,  dominoes,  eating,  drinking,  looking  at  books  or  pictures,  to 
the  purpose  successfully.  The  artist  here  follows  his  feelings,  which 
will  discern  the  right  from  the  false  very  well.  To  cultivate  this  feel- 
ing, a  study  of  the  art-rules  alone  will  not  suffice,  thereto  the  study  of 
celebrated  works  of  art,  portraits,  and  genre  pictures  of  old  and  new 
masters  is  necessary.  Who,  however,  wishes  to  finish  the  cultivation 
of  his  form  and  line  feeling,  should  delineate  after  antique  models. 
Here  the  effect  of  outlines  and  lines  are  learned.  One  thing  is  yet 
to  be  considered.  Much  that  in  painting  has  an  infinitely  charming 
effect,  would,  photographed,  have  a  quite  indifferent  one.  Knauss 
painted  his  daughter,  standing  with  both  feet  firmly  set,  in  front 
of  an  empty  dark  background,  looking  at  the  beholder  with  her  slate 
in  her  hand.  The  pose  is  as  simple  as  possible.  A  photographer 
who  would  choose  the  same  pose,  for  the  same  child,  would  probably 
be  accused  of  want  of  idea.  The  painted  picture,  nevertheless,  ap- 
pears so  infinitely  charming,  through  the  exquisite  painting,  the  fine- 
ness of  the  carnation,  the  wonderful  characteristic  of  the  natural  child- 
face,  that  the  simple  pose  does  not  disturb  the  picture  at  all.  The 
excellent  painter  has,  without  regard  to  the  colors,  namely,  by  the  true 
reproduction  of  the  characteristics  (which  is  hard  and  seldom  accom- 
plished by  the  photographer),  so  much  in  his  favor  against  the  pho- 
tographer, that  he  can  among  other  things,  slight  his  miserable  expe- 
dients. 

Fig.  133. 


The  arrangement  of  landscapes  admits  of  much  more  freedom,  as 
we  have  already  seen  above,  in  speaking  of  the  sketch  by  Paton 
(Fig.  128).  The  shrubbery  to  the  right  finds  its  symmetrical  oppo- 
site in  the  two  trees  to  the  left. 


ARRANGEMENT. 


341 


In  the  same  manner  in  a  picture  of  the  sea,  which  intentionally  has 
been  enlivened  by  a  boat  or  a  ship,  the  latter  effect  must  be  balanced 
by  massive  rocks  (Fig.  133).  Clouds  also  are  often  happily  employed 
to  produce  this  equilibrium. 


Fig.  134. 


are 


Accessories  are  of  great  importance.   Very  often  the  simplest  things 
of  the  greatest  advantage.    For  instance,  the  accompanying  pic- 


FiG.  135. 


342 


THE  PRACTICE  OF  PHOTOGRAPHY. 


resent  one  and  the  same  object,  and  correspond  exactly,  excepting  the 
black  spots, — the  boat  in  the  river,  and  the  tree  on  the  river  bank, 
which  in  the  one  are  wanting.  In  comparing  the  two  we  feel  at  once 
the  importance  of  the  black  parts  in  the  lowest  point  of  the  angle, 
which  is  formed  by  the  perspective  lines  of  the  castle  and  the  river. 
In  the  second  picture,  where  the  boat  and  the  river-bank  are  left  out 
altogether,  the  castle  looks  as  if  the  foundation  had  been  removed 
from  under  it.  The  lines,  which  run  towards  a  distant  point,  seem  to 
lack  union  and  regulation ;  the  distance  enters  the  foreground,  and 
the  separate  parts  do  not  stand  in  the  proper  relation  to  one  another. 
In  Fig.  134,  where  the  boat,  tree,  etc.,  are  present,  every  part  occu- 
pies its  proper  position,  and  we  have  a  feeling  of  completeness  which 
is  wanting  in  Fig.  135. 

I  would  advise  the  student  to  study  with  care  the  principal  landscape 
pictures  of  our  great  masters, — Claude  Lorrain,  Schirmer,  Lessing, 
Hildebrandt,  and  others.  In  all  of  them  he  will  find  interesting  ex- 
amples of  what  has  been  said  above. 

LINES  AND  OUTLINES. 

Before  photography  was  invented  the  so-called  silhouettes  were 
much  liked  as  cheap  pictures.  They  represented  nothing  but  the 
outlines  of  the  figure,  generally  in  profile.  Everything  else  was 
empty  (as  the  treasury  of  the  French  minister  (Silhouette)  from  whom 
these  pictures  derived  their  name).  In  spite  of  this  emptiness  the  pic- 
tures were  pleasing,  and  how  much  effect  can  be  produced  with  them 
is  shown  by  the  recent  silhouettes  of  Konewka,  who  really  has  pro- 
duced charming  pictures  in  this  branch,  and  the  want  of  filling  up  in 
his  pictures  is  scarcely  felt.  This  shows  of  how  much  importance 
outlines  are.  The  influence  is  felt  everywhere,  not  only  in  the  empty 
silhouette,  but  in  every  picture. 

Every  thinking  artist  who  desires  to  reproduce  an  object  first 
studies  its  outlines.  He  allows  his  eye  to  glide  over  the  lines,  and 
tries  to  find  the  beauty  of  their  curves.  He  follows  the  changes  of 
the  stronger  and  the  weaker  one,  the  longer  and  shorter,  their  wind- 
ings, and  easy  combinations.  Let  us  study,  for  instance,  the  outlines 
of  the  figures  of  the  Madonna  Aldobrandini  by  Raphael  (Fig.  137), 
one  of  the  most  magnificent  early  works  of  the  great  Urbini,  let  us 
place  alongside  a  similarly  arranged,  and  according  to  photographic 
notions,  successful  children's  picture,  and  we  will  feel  at  once  the 
enormous  difference.  The  vast  public  of  course  does  not  see  such. 
It  gapes  at  the  faces  with  the  remark,  "A  pretty  face,"  or  the  opposite. 
A  painting  is  refused  that  the  artist  has  painted  dress,  draperies,  form 


LINES  AND  OUTLINES. 


343 


of  body,  color,  illumination,  and  shadow,  and  motion,  with  the 
greatest  care,  and  not  noticed.  But  not  only  the  outlines  speak  in  the 
picture,  but  the  whole  contour  generally,  whether  it  be  formed  by 
the  limbs,  seams,  folds,  accessories,  or  draperies. 

I  have  already  shown  by  Fig.  126  above,  what  an  unpleasant  effect 
is  produced  by  parallel  lines,  or  when  the  limbs  are  placed  at  right 
angles  to  each  other,  like  the  legs  of  a  saw-horse.  Just  as  ugly  are 
zigzag  lines.  See,  for  instance,  the  Turkish  lady  (Fig.  127).  The 
kinked  breeches  make  up  a  zigzag  formed,  highly  unpleasant  effect, 
producing  ugly  outlines ;  add  thereto  the  lines  of  the  kinked  pleats 
running  to  and  fro  cm  the  surface,  and  finally,  the  decidedly  ugly 
angle  produced  by  the  elevated  leg  on  the  supporting  one,  without 


speaking  of  the  ugly  outline  of  the  whole  figure.  In  every  artistically 
beautiful  picture  there  exists  a  wonderful  degree  of  harmony  of 
lines,  and  even  a  photograph  can  do  justice  to  this. 

Let  me  again  refer  to  the  picture  by  Jagemanu  (Fig.  123).  The 
edge  of  the  undercoat  slopes  from  the  right  hand  upwards,  and  is 
continued  in  the  line  of  the  neck.  The  latter  sweeps  on  the  other 
side  downwards,  in  the  contour  of  the  face  and  the  forehead,  and  is 
finally  lost  in  the  edge  of  the  same  coat.    The  outline  of  the  hand 


344 


THE  PRACTICE  OF  PHOTOGRAPHY. 


which  holds  the  book  is,  starting  from  the  little  finger,  continued  in 
the  same  elegant  manner  in  the  contour  of  the  overcoat,  ascends  next 
to  the  throat,  descends  on  the  other  side,  and  ends  in  the  slightly 
curved  index  finger  of  the  left  hand,  and  almost  voluntarily  the  eye 


Fig.  137. 


LINES   AND  OUTLINES. 


345 


follows  the  direction  of  this  finger,  and  continues  the  sweeping  line 
in  order  to  ascend  again  to  the  edge  of  the  book,  the  thumb,  and  the 
contour  of  the  inner  coat. 

This  shows  how  several  outlines  may  combine  to  form  a  main  line, 
and  how  even  the  hair  may  follow  the  sweep  of  the  curves. 

I  would  now  call  attention  to  the  "  genre  "  style  of  Terburg  (Fig. 
136).  We  see  the  contour  of  the  coat  of  the  lady  continued  in  the 
folds  of  the  table-cloth,  ascend  to  the  corner,  and  continue  in  the 
right  arm  of  the  knight,  continue  again  in  the  outline  of  the  figure 
standing  in  the  background,  and  thus  gradually  carried  back  to  the 
lady.  The  back  figure  in  the  terzetto  would,  if  placed  by  itself,  not 
be  free  from  objection.  It  is  a  fault  when  neither  arm  nor  leg  resolves 
itself  into  outline,  and  when  the  head  is  squeezed  in  between  the  shoulders, 
as  in  this  last-named  figure. 


Fig.  138. 


Such  figures  are  bad  unless  the  action  represented  should  demand 
such  a  position.  But  in  trying  to  give  a  sharply  marked  outline  we 
can  do  "too  much  of  a  good  thing,"  and  instead  of  expressing  calm- 
ness and  dignity  by  a  simple  profile,  we  may,  by  too  lively  an  ar- 
rangement of  outlines,  do  exactly  the  reverse.    We  need  not  look 


846 


THE  PRACTICE  OF  PHOTOGRAPHY. 


far  for  examples.  There  are  thousands  of  portrait  photographs,  in 
which  the  calm  and  dignified  features  of  an  old  man  are  represented 
by  zigzag  lines,  lacking  all  the  elements  of  beauty. 

In  its  outlines,  the  picture  by  Jagemann  (Fig.  123),  may  be  called 
a  success.  Only  one  thing  is  annoying,  the  projecting  back  of  the 
chair  behind  the  left  arm  and  the  shoulders,  which  are  drawn  back 
too  much,  and  give  to  the  figure  a  weak  appearance. 

The  lively  outlines  correspond  perhaps  with  the  character  of  the 
subject,  but  they  would  be  ill-suited  to  an  older  person.  A  little 
more  lively  profile  would  be  desirable  for  the  female  parts  of  the  pic- 
ture by  Metzu  (the  lovers)  (Fig.  138),  but  it  may  be  objected  that  the 
beauty  turns  a  cold  shoulder  to  the  caresses,  and  that  the  quiet  out- 
lines correspond  exactly  with  her  indifferent  humor. 

It  is  difficult  to  explain  to  any  one  fully  the  beauty  of  the  lines. 
It  is  a  matter  of  feeling.  I  can  only  call  attention  to  the  first-class 
masterpieces  in  painting  and  sculpture.  For  instance,  the  lines  and 
general  contour  in  the  Madonna  of  Kaphael  (Fig.  137).  In  these 
wonderfully  soft  outlines,  which  look  as  if  they  were  laid  on  the 
canvas  with  the  breath,  is  such  a  charming  harmony  that  everything 
which  the  photographer  has  ever  made  with  his  camera  looks  flat  and 
weak  compared  with  it.  On  such  works  the  disciple  of  art  may  ex- 
ercise his  appreciation  of  outlines. 

In  landscapes  also  contour  and  lines  play  an  important  part.  Even 
the  ordinary  admirer  of  nature  distinguishes  between  elegant  and 
clumsy  outlines  of  mountains  and  trees.  In  architectural  pictures 
many  parallel  lines  converge  towards  the  point  of  "  disappearance ;" 
they  direct  the  eye  to  great  distances,  and  even  without  such  archi- 
tectural lines  we  will  feel,  in  a  well-composed  landscape,  a  certain  har- 
mony in  the  sweep  of  the  lines,  as,  for  instance,  in  the  curve  of  the 
shore  which  is  lost  in  the  distance  of  the  picture  (Fig.  133) ;  also  in 
the  contour  of  the  mountains,  all  of  which  lead  the  eye  to  the  same 
distance.  Clouds  are  wanting  in  the  above  sketch  ;  if  an  artist  would 
add  them  to  the  picture  their  outlines  would  have  to  harmonize  with 
those  of  the  mountains  and  shore. 

In  the  sketch  of  Windsor  Castle  (Figs.  134,  135)  the  outlines  of 
the  clouds  descending  to  the  right  form  a  contrast  with  the  contour  of 
the  architectural  objects  which  descend  to  the  left. 

DRESSES  AND  DRAPERIES. 

Our  climate  compels  us  to  cover  ourselves,  as  a  protection  against 
wind  and  weather,  with  clothing,  the  form  of  which  is  regulated  by 


DRESSES  AND  DRAPERIES. 


347 


sex,  nationality,  the  age,  and  is  also  modified  to  a  very  large  extent 
by  the  individual  taste  and  fashion. 

In  general  the  modern  dress  consists  of  bag-like  pieces,  which  are 
sewed  or  buttoned  together — sleeves,  pants,  vest,  coat — quite  in  con- 
trast with  the  costume  of  the  ancients,  which  consisted  in  simple 
pieces  of  some  material  which  were  thrown  in  picturesque  folds  around 
the  body.  At  present  the  fop  shows  himself  by  the  cut  of  his  clothes, 
which  correspond  with  the  latest  number  of  the  journal  of  fashion. 
At  the  time  when  classic  Greece  had  reached  its  height  the  greatest 
elegance  showed  itself  in  the  beauty  of  the  folds  of  the  drapery. 
Pericles  was  celebrated  for  the  manner  in  which  he  threw  his  cloak 
about  his  body. 

We  find  the  antique  costume  in  numberless  statues,  and  even  where 
the  figure  is  completely  draped  we  can  discern  the  form  of  the  body 
distinctly.  Shape  and  motion  of  the  covered  limbs  are  distinctly  vis- 
ible. To  this  principle,  from  which  the  ancients  never  deviated,  our 
great  modern  artists  strictly  adhere,  and  where  it  has  been  overlooked 
the  work  will  not  even  satisfy  the  common  inartistic  observer. 

Our  feelings  demand  motives.    Why  is  there  a  depression  in  the 
drapery  ?   Because  underneath  it  is  the 
cavity  between  the  arm  and  the  body. 
Why  is  there   an  elevation   in  the 
dress  ?    Because  it  indicates  the  knee. 

When  we  contemplate  the  (in  itself) 
beautiful  Mary,  by  H.  Van  Eyck 
(Fig.  139),  we  find  the  dress  does  not 
indicate  in  any  way  the  foot,  the  leg, 
or  the  knee,  and  one  cannot  tell  (at 
least  not  from  the  woodcut)  whether 
the  figure  is  kneeling  or  standing.  No 
one  will  call  such  drapery  beautiful. 

To  further  show  a  photographic  ex- 
ample, see  the  Turkish  lady  (Fig.  127), 
whose   kinked   breeches  wholly  hide 

the  form  of  the  legs  contained  therein,  Madonna,  after  Van  Eyck. 

so  that  the  elevated  leg  appears  as  a 

shapeless  mass.  Compare  with  this  Fig.  140,  where  the  forms  are 
much  more  clearly  indicated  through  the  covering  of  the  Madonna 
of  Fra  Bartolommeo.  It  is  not  difficult  to  perceive  that  one  leg 
is  kneeling,  while  the  other  one  is  stemmed  in  support.  The  position 
of  the  knee  is  clearly  indicated.  Even  the  heel  of  the  left  foot  is 
plainly  shown.    Much  the  same  arrangement  we  see  in  the  arm. 


348 


THE  PRACTICE  OF  PHOTOGRAPHY. 


How  strictly  modern  artists  conform  to  the  rule  that  the  folds  of 
the  drapery  must  conform  to  the  forms  of  the  body  is  shown  by  the 
fact  that  the  sculptors  first  model  their  figures  naked,  and  afterwards 
place  the  drapery  on.  Some  modern  fashions  make  this  conforming 
of  the  clothing  to  the  form  of  the  body  an  impossibility  in  photogra- 
phy, as,  for  instance,  the  use  of  hoop  skirts. 


Fig.  140, 


Madonna,  after  Fra  Bartolorrmieo. 


In  such  cases  the  artist  must  submit  to  the  ruling  fashion,  for  it 
would  be  wrong  to  persuade  a  modern  lady,  not  an  actress,  to  discard 
her  crinoline  in  order  to  mark  by  a  suitable  drapery  the  position  of 
the  knees,  the  legs,  etc.  (The  fashion  alluded  to  is  now  changed, 
1874.) 

In  the  arrangement  of  the  clothing  and  draperies,  in  so  far  as  the 


DRESSES   AND  DRAPERIES. 


349 


fashions  do  not  interfere,  attention  should  be  given  that  the  points  of 
the  shoulders,  elbows,  hip,  knee  and  foot  are  recognizable,  also  the 
broad  surfaces  of  the  chest,  the  loins,  etc.  On  the  latter,  depressions 
look  very  bad,  while  they  are  well  suited  to  mark  cavities,  as  for  in- 
stance, between  the  body  and  arm,  between  the  legs,  etc.  (Fig.  112.) 

How  important  a  part  the  drapery  plays,  in  giving  a  more  or  less 
elegant  flow  to  the  lines,  the  examples  which  we  have  given  above 
will  show.  Good  artists  are  always  anxious  to  modify  the  baggy  and 
unyielding  forms  of  our  modern  garments,  by  a  piece  of  cloth  or  a 
cloak,  in  order  to  drape  the  figure  artistically,  and  the  more  stiffness 
the  fashion  or  the  clothing  prescribes  the  more  excusable  is  the  artist 
if  he  resorts  to  these  subterfuges.  In  the  soldiers  of  Kauch  we  gener- 
ally find  the  cloak  (Blucher,  Scharnhorst,  Gneisenau),  the  flowing 
lines  of  which  agreeably  contrast  with  the  stiff  lines  of  the  uniform, 
and  which  splendidly  mark  the  movements  of  the  figure.  Photogra- 
phers in  particular  like  to  resort  to  these  accessories,  and  especially 
the  sculptor  Adam  Salomon,  who  goes  perhaps  too  far  in  this  respect, 
by  giving  to  his  sitters  draperies  unknown  to  modern  fashion.  For- 
tunately cloaks,  havelocks,  and  Scotch  plaids  are  the  ready  means  at 
the  hands  of  the  artist  to  produce  the  desired  effects;  still  better  ad- 
vantages are  offered  in  the  female  costume,  where  arabs,  shawls,  veils, 
etc.,  supply  a  variety  of  draperies.  But  they  should  not  be  given  to 
persons  by  whom  the  wearing  of  such  articles  is  unusual,  and  who, 
perhaps,  even  protest  against  their  employment. 

It  is  not  the  purpose  of  photography  to  represent  motion,  but  on 
the  contrary  a  resting  pose,  and,  therefore,  it  loses  that  important  ele- 
ment of  marking  the  forms  of  the  body  which  the  artist  possesses  in 
the  flowing  drapery. 

It  must  not  be  supposed,  however,  that  the  artist  can  let  the  gar- 
ments fly  about  at  will,  but  their  motions  must  have  a  motive,  which 
we  must  be  able  to  explain  from  natural  causes. 

It  is  the  resistance  of  the  air  in  Thorwaldsen's  "Night"  (Fig.  131) 
which  presses  the  drapery  to  the  form,  and  brings  out  the  beautiful 
proportions. 

Such  motives  we  demand  also  in  a  resting  pose.  Byron,  by  Thor- 
waldsen  (Fig.  141),  has  his  cloak  over  the  shoulders,  in  order  to  hide 
the  right  half  of  the  body  completely.  The  hand  rests  on  the  knee, 
and  this  causes  the  folds  descending  from  the  shoulder  to  be  tightly 
drawn,  which  with  the  depression  between  the  arm  and  the  upper  leg, 
plainly  indicates  the  form  of  the  body. 

Frequently  we  help  ourselves  artificially  by  purposely  pressing  the 
draperies  into  the  cavity  between  arm  and  body,  or  between  the  legs, 


350 


THE  PRACTICE  OF  PHOTOGRAPHY. 


but  such  an  arrangement  has  to  be  managed  with  exceeding  care,  in 
order  to  look  artistic  and  not  artificial. 

The  material  of  the  garment  plays  a  very  important  part.  Starched 
linen  and  highly-finished  silk  give  hard  and  unpleasant  folds.  Cotton 
is  better,  but  woollen  material  is  the  softest  and  most  harmonious. 

The  gloss,  the  color,  and  the  thickness  of  the  material,  also  require 
the  most  diligent  study  of  the  artist.  For  the  painter  color  and  high- 
lights are  welcome  objects  to  show  his  skill.  The  photographer  is 
often  driven  to  despair  by  their  stubbornness,  as  the  color  is  either  in- 
effectual, or  the  high-lights  produce  ugly  white  spots.  Salomon  is  right. 
Starting  from  the  principle  that  the  head  should  be  brightest,  he 
covers  the  light  clothing  which  would  make  the  head  appear  dark 
with  dark  drapery.  He  gives  the  preference  to  velvet  drapery,  not 
black  silk  velvet,  but  violet  brown,  or  reddish  cotton  velvet.  This 
material  arranges  itself  in  soft  and  well-rounded  folds,  while  the  high- 
light on  the  prominent  points  is  gently  moderated.  A  piece  of  dark 
crape  or  a  veil  is  sometimes  very  valuable  in  modifying  bright  cloth- 
ing, and  has  the  advantage  that  the  light  dress  shows  through,  while 
a  dark  drapery  hides  it  completely. 

Attention  should  be  given  to  the  parts  without  folds,  and  also  to 
the  elevated  and  depressed  portions.  The  folds  should  flow  evenly, 
and  not  be  interrupted  by  numberless  rumples,  as  is  often  the  case 
when  the  garments  have  been  in  use  for  a  length  of  time.  I  have  seen 
a  picture  of  Iphigenia,  by  Jagemann,  where  the  classic  robe  was 
splendidly  arranged,  but  where  the  many  rumples  disturbed  the  effect. 
The  artist  (painter  or  sculptor)  leaves  these  things  out,  and  he  has  a 
right  to  do  so. 

Folds  generally  do  not  run  in  straight  lines,  but  appear  on  the 
curves  of  the  body,  or  where  the  dress  touches  the  floor,  and  the  folds 
become  broken. 

Such  breaks  are  very  different  in  their  nature ;  sometimes  they  are 
sharply  cornered,  sometimes  more  rounded,  sometimes  quite  flat,  and 
at  others  deeper.  When  they  run  in  a  zigzag  line,  backward  and  for- 
wards, they  disturb  the  feeling,  and  lack  beauty  (Fig.  139).  The 
seam  appears  under  as  manifold  aspects  in  our  modern  tiresome  cos- 
tumes ;  it  generally  is  lost  in  monotonous  lines,  as,  for  instance,  the 
seams  of  our  coats,  which  are  cut  below  in  a  horizontal  line  of  almost 
architectural  stiffness. 

Still  more  disagreeable  is  the  dress-coat,  with  the  right-angled  cut 
on  both  sides,  which  lacks  all  purpose. 

But  even  in  garments  which  fulfil  the  purposes  of  drapery  much 
better  the  seam  is  generally  neglected.    The  artist  is  often  satisfied 


DRESSES  AND  DRAPERIES. 


351 


with  having  produced  a  few  artistic  folds,  and  pays  no  attention  to 
the  lines  of  the  corners. 

Of  how  much  importance  these  are,  a  glance  at  the  seam  of  the 
drapery  of  Thorwaldsen's  Night  (Fig.  131)  will  show  at  once. 

Fig.  141. 


Byron,  after  Thorwaldsen. 


Lively  and  animated  at  the  feet,  the  upper  parts  sweep  in  various 
directions,  and  give  rise  to  a  charming  play  of  lines.  When  such  an 
animation  of  the  seam  is  but  an  exceptional  case  in  quiescent  figures, 
and  particularly  difficult  in  our  modern  costumes,  still  the  pictures  of 
Terburg  and  Mieris  (Figs.  136,  138)  teach  us  that  with  all  simplicity 
we  can  avoid  monotony.  The  lively  curve  of  the  seam  of  the  cloak  of 


352 


THE   PRACTICE   OF  PHOTOGRAPHY. 


Byron  forms  a  pleasing  contrast  to  the  somewhat  stiff  and  monotonous 
lines  of  his  modern  costume. 

A  peculiar  kind  of  folds,  which  are  particularly  annoying  to  the 
photographer,  are  the  folds  which  show  themselves  in  our  clothing 
after  they  have  been  in  use  for  some  time.  They  manifest  themselves 
particularly  in  the  arm  and  knee  joints.  They  are  elevations  or  in- 
dentations which  are  visible  even  in  the  standing  figure,.and  which 
no  pulling  and  twisting  will  remove.  They  are  particularly  offensive 
when  they  show  themselves  above  or  below  the  knee.  Attention 
should  be  paid  to  these  folds,  and  they  should  be  placed  at  the  spot 
where  they  properly  belong,  i.  e.,  at  the  knees  or  the  elbows. 

Sometimes  a  comical  effect  is  intentionally  produced  by  placing 
these  folds  in  the  wrong  place,  and  by  giving  them  a  particular 
prominence. 

The  treatment  which  modern  costumes  require,  in  order  to  give  an 
artistic  effect,  we  can  best  learn  from  the  works  of  modern  masters. 
They  should  be  studied  whenever  a  chance  offers  itself.  We  should 
observe  the  contour,  the  folds,  the  surfaces,  and  seams.  That  is  the 
only  way  to  sharpen  our  judgment. 

The  hair  requires  similar  management  to  the  drapery,  but  in 
speaking  of  the  hair  I  do  not  refer  to  the  dropsical  modern  produc- 
tions, consisting  of  chignons  and  other  monstrosities,  but  refer  to  the 
free  flowing  natural  article.  I  will  not  sit  in  judgment  on  every  arti- 
ficial curl,  however.  They  are  sometimes  very  acceptable  in  produc- 
ing a  picturesque  arrangement. 

The  hair  which  hangs  down  monotonously  without  variation  is 
like  the  drapery  without  a  fold.  The  ancient  sculptors  enlivened  it 
by  pouring  it  into  wavy  lines.  The  effect  is  splendid  when  in  nobly 
curved  lines  it  flows  around  the  head,  descends  to  the  shoulders,  and 
harmoniously  loses  itself  in  the  lines  of  the  drapery.  A  hat  with  a 
waving  plume  or  a  veil  will  produce  a  beautiful  harmony  with  the 
hair.  The  portrait  painters  of  all  times  have  known  how  to  take  ad- 
vantage of  this. 

I  might  speak  here  of  drapery  in  the  landscape.  Seriously  speak- 
ing, what  is  the  foliage  of  the  trees  other  than  beautiful  natural  dra- 
pery ?  The  difference  is  that  the  trees  wear  their  garments  in  summer- 
time, while  men  don  their  most  elaborate  costumes  in  winter.  Here 
also  the  aesthetic  sense  demands  that  the  skeleton  of  the  trees,  the 
branches,  shall  be  visible  in  the  foliage.  The  elevations  and  depres- 
sions must  find  their  cause  in  the  disposition  of  the  branches,  and  in 
this  consists  the  difference  between  beautiful  and  ugly  trees.    In  the 


POSITION  AND  STANDPOINT. 


353 


former  the  contour  of  the  foliage  gives  us  an  insight  in  the  structure 
of  the  branches,  although  the  latter  are  not  directly  visible. 

POSITION  AND  STANDPOINT. 

(a.)  The  Arrangement  of  Human  Figures. 

In  the  chapter  on  arrangement  I  have  already  called  attention  to 
the  fact  that,  in  a  standing  human  figure,  the  centre  of  gravity  must 
not  be  lost  sight  of.  In  a  figure  resting  on  one  foot  the  line  of  the 
centre  of  gravity  proceeds  from  the  throat  to  the  inner  ankle  bones 
of  the  foot  on  which  the  person  rests.  If  the  lines  fall  outside  the 
same,  then  the  figure  is  not  sufficiently  supported,  and  should  have  a 
support  against  which  it  can  lean.  A  position  where  the  body  rests 
equally  on  both  feet  the  artist  will  very  seldom  select,  not  even  for  a 
soldier.  But  where  a  body  rests  on  one  foot  (Fig.  144),  and  where 
the  other  has  free  play,  the  hip  on  the  side  of  the  supporting  leg  will 
be  higher  than  the  other.  It  will  also  easily  be  observed  that  the 
shoulder  over  the  supporting  leg  is  a  little  lower  than  the  other. 

The  hip  lines  and  shoulder  lines  are  no  longer  parallel.  Painters 
pay  particular  attention  to  this,  and  photographers  should  do  the 
same.  There  are  persons  who  habitually  carry  one  shoulder  lower 
than  the  other.  Such  persons  should  not  be  placed  in  such  a  manner 
that  the  body  rests  on  the  foot  which  corresponds  with  the  lower 
shoulder.  The  natural  fault  would  only  appear  exaggerated.  The 
head  appears  more  lively  when  it  has  a  different  direction  from  the 
chest.  The  eyes  follow  the  head  ;  for  instance,  if  the  head  is  turned 
to  the  right  the  eyes  will  take  the  same  direction,  unless  they  should 
look  straight  ahead.  In  no  instance  is  it  admissible,  where  the  face 
bears  a  calm  expression,  that  the  eyes  should  be  turned  to  the  right 
while  the  face  is  turned  to  the  left.  By  a  very  slight  turn  or  change  in 
the  direction  of  the  head  on  the  one  side  and  the  apparatus  on  the  other, 
the  outlines  of  the  head  may  become  completely  changed.  The  turn  of 
the  head  is  generally  left  to  the  photographer,  and  he  generally  pre- 
fers to  direct  the  eyes  to  the  shaded  side.  Artists,  on  the  contrary, 
are  in  the  habit  of  turning  the  head  in  the  direction  of  the  highest 
shoulder. 

The  free  leg,  in  contradistinction  to  the  supporting  leg,  is  not 
limited  in  the  choice  of  position.  It  can  be  moved  forward  or  it  may 
recede,  but  the  position  of  the  opposite  arm  depends  on  the  position 
of  the  leg.  We  notice  in  walking  how  the  left  leg  corresponds  in  its 
motions  with  the  right  arm,  and  vice  versa.  The  right  arm  and  the 
left  foot  are  raised  simultaneously  in  order  always  to  maintain  the 

23 


354  THE  PRACTICE  OP  PHOTOGRAPHY. 

balance.  But  from  an  artistic  standpoint  it  is  likewise  justifiable 
that  the  left  arm  and  the  right  foot  should  move  in  contrary  direc- 
tions, so  as  to  avoid  parallel  lines. 

When  the  upper  part  of  the  "free  leg"  progresses,  it  is  customary 
to  let  the  upper  arm  on  the  other  side  recede  and  the  forearm  progress 

Fig.  142. 


(see  the  annexed  figure  of  the  Levite).  Also,  in  order  to  avoid  par- 
allel motion,  when  one  arm  is  raised  the  other  hangs  down  by  the 
side  (see  the  annexed  figure  of  the  Pharisee).  In  short,  the  natural 
contrast  in  motion,  which  shows  itself  in  walking,  we  try  to  maintain 
in  the  quiescent  figures,  and  this  enables  the  artist  to  give  it  an  ani- 
mated appearance.  Artists  pay  attention  to  the  smallest  details,  even 
in  the  positions  of  the  limbs.  In  an  outstretched  arm  the  hand  should 
have  a  different  direction  from  the  arm,  and  to  the  hand  itself  the 
most  scrupulous  attention  is  given.  Next  to  the  head  the  hand  is  the 
most  expressive  and  interesting  part  of  the  body. 


POSITION   AND  STANDPOINT. 


355 


Beautiful  hands  are  exceedingly  rare,  and  the  photographer  is  but 
too  often  compelled  to  show  them  as  little  as  possible;  but  their  natu- 
ral ugliness  is  increased  by  an  ungraceful  position.  Let  us  look  at 
the  hands  by  our  first  painters  and  sculptors.  Every  finger  of  the 
unemployed  hand  is  independent  and  distinguishes  itself  from  its 
neighbor  by  its  motion,  while  in  many  photographs  the  fingers  appear 
as  if  they  were  glued  together  (look  at 
the  figure  of  a  grasping  and  supporting 
hand,  Fig.  143;  also  the  hands  in  the 
portrait,  Fig.  141).  We  will  also  find 
in  our  master-pieces,  without  much  diffi- 
culty, that  the  index  finger  plays  a  promi- 
nent part  amongst  the  longer  fingers  of 
the  hand. 

It  is  difficult  for  the  photographer  to 
separate  the  fingers  of  his  model.  A 
simple  expedient  to  give  to  the  stiff  fin- 
gers a  somewhat  more  lively  expression 
consists  in  placing  a  roll  of  paper  in  the  hand  of  the  sitter.  The 
fingers  will  place  themselves  around  this,  similar  to  the  portrait  (Fig. 
142).  By  gently  removing  the  roll,  the  fingers  will  remain  in  a  tol- 
erably graceful  position. 

We  must  of  course  take  the  individuality  of  our  model  into  account. 
It  would  be  ridiculous  to  bring  the  horny  hand  of  a  laboring  man  or 
a  washerwoman  into  such  a  position.  The  position  of  the  hand  de- 
pends of  course  upon  the  object  that  has  been  held  by  it.  A  light 
object,  for  instance,  like  a  book,  is  seized  in  a  playful  manner,  while 
a  heavy  one,  like  a  lance  or  a  spear,  is  more  firmly  grasped;  but  even 
here  the  index  finger  does  not  grasp  as  firmly  as  the  others.  To  seize 
a  light  book  in  the  same  manner  as  a  heavy  weapon  would  appear 
comical ;  and  to  seize  a  heavy  weapon  as  gracefully  as  a  plaything 
would  appear  weak. 

All  that  has  been  said  in  the  above  pages  in  regard  to  standing 
figures  applies,  the  nature  of  the  support  excepted,  also  to  sitting 
ones.  Both  legs  are  here  at  liberty.  On  account  of  the  inactivity 
of  arms  and  legs  there  exists  a  greater  freedom  of  motion  and  of  ar- 
rangement. Above  everything  else  a  parallel  position  of  the  arms, 
or  of  the  legs,  should  be  avoided.  Fig.  126  furnishes  a  warning  ex- 
ample. 

With  such  representations  photography  has  nothing  to  do ;  the 
representation  of  objects  at  rest  is  her  province. 

I  must  still  call  attention  to  the  differences  in  age  and  sex.  Children 


356 


THE  PRACTICE  OF  PHOTOGRAPHY. 


and  women  are  differently  constructed  from  men.  They  stand  and 
walk  differently.  The  child,  for  instance,  does  not  know  a  supporting 
leg  nor  a  free  leg,  except  in  a  highly  developed  state.  It  stands  firm 
on  both  legs.  The  masculine  body  is  firmer,  more  muscular,  and  less 
fleshy. 

In  women  and  children  the  soft  parts  are  more  developed.  Look 
at  the  hand  of  a  child.  It  looks  like  a  cushion.  The  large  size  of 
the  head  of  a  child  is  well  known.  The  oval  of  the  male  head  is 
broader  below  than  the  female.  The  eye  in  women  is  located  a  little 
lower  than  in  men ;  the  ears  and  the  nose  are  a  little  shorter,  and  the 
mouth  somewhat  smaller. 

Of  course  there  are  numberless  exceptions  to  this  average  rule,  ac- 
cording to  race,  individuality,  manner  of  living,  and  development 
from  gymnastic  exercises.  Place  a  woman  who  has  to  make  her 
living  with  her  handiwork,  alongside  of  a  lady  who  spends  her  time 
in  idleness.  There  are  no  two  individuals  exactly  alike,  and  no  one 
knows  it  better  than  the  photographer.  Let  him  try  to  repeat  a 
pretty  pose,  with  which  he  was  successful  with  one  model,  with  another 
person,  and  he  will  soon  find  the  difficulties.  It  will  not  do,  and  in 
spite  of  all  his  care  it  will  always  turn  out  something  different,  even 
if  the  two  persons  look  as  nearly  alike  as  can  be.  It  is,  therefore, 
generally  speaking,  superfluous  to  give  rules  for  making  positions. 

I  have  repeatedly  referred  to  the  picture  (Fig.  123)  by  Jagemann. 
The  chest  is  turned  towards  the  left  upper  leg.  This  gives  a  lively 
expression.  It  is  increased  by  the  turn  of  the  head,  in  the  reproduc- 
tion of  which  unfortunately  the  xylographer  has  not  succeeded.  The 
whole  figure  becomes  animated,  which  seems  almost  as  if  it  were 
carried  too  far,  but  which  in  this  instance  corresponds  exactly  with 
the  character  of  the  individual.  It  would,  however,  be  foolish  if  we 
would  give  a  similarly  animated  pose  to  another  person  of  a  calmer 
temperament.  Here  slight  co?itrasts  are  by  far  preferable.  When  a 
stiff-jointed  old  man  places  both  his  legs  in  parallel  lines,  we  must 
admit  that  this  is  perfectly  in  order,  and  a  quiescent  turn  of  the  head 
should  be  selected  for  him. 

What  has  been  said  in  regard  to  single  persons  applies  with  equal 
force  to  groups,  for  a  group  is  nothing  but  a  number  of  individuals. 
Yet  in  the  arrangement  of  each  single  figure  the  complexion  of  the 
whole  must  be  kept  in  view,  and  the  building  up  of  the  group  must 
be  carried  on  in  an  artistic  manner.  The  larger  the  number  of  per- 
sons, the  greater  will  be  the  difficulty,  and  we  have  to  add  to  this, 
that  besides  the  artistic  conditions,  we  have  to  take  into  account  the 
optical  difficulties,  which  require  that  every  character  should  appear 


POSITION  AND  STANDPOINT. 


357 


on  the  ground-glass  sharply  defined  and  without  any  distortion  ;  the 
latter  compels  us  to  adopt  a  circular  arrangement,  where  the  concave 
side  of  the  circle  is  turned  towards  the  lens.  When  this  is  done  the 
marginal  figures  will  appear  sharp,  as  the  whole  picture  is  now  flat. 
How  much  the  circle  must  be  curved  inwardly  depends  entirely  on 
the  nature  of  the  objective,  which  yields  more  or  less  curved  pictures. 
How  the  groups  are  to  be  artistically  arranged  we  have  already  shown 
above.  With  all  pictures  without  exception  clearness  in  the  arrange- 
ment is  demanded. 

When  in  groups  the  hands  rest  on  different  shoulders,  an  arrange- 
ment much  in  vogue  in  student's  pictures,  and  where  one  is  at  a  loss 
to  say  to  whom  the  different  limbs  belong,  and  when  the  legs  of  a 
group  form  a  confused  mass,  we  must  call  the  arrangement  confused. 
Such  want  of  clearness  very  often  happens  also  in  single  portraits) 
when,  for  instance,  one  hand  lifts  the  drapery  and  causes  character- 
istic folds ;  but  when  the  lifting  hand  itself  is  invisible,  we  must  call 
the  representation  devoid  of  clearness.  It  further  lacks  clearness 
when  expressive  parts  are  covered  up.  It  is  mentioned  as  a  fault  in 
the  group  of  the  Amazon,  by  Kiss,  that  the  three  heads — the  head  of 
the  Amazon,  of  the  horse,  and  the  panther — cannot  be  seen  from  any 
side  all  at  once.  It  is  also  a  fault  to  cover  a  limb  which  performs  a 
characteristic  function.  I  know  of  a  picture  where  it  is  intended  to 
represent  a  letter-writer,  where  the  writing  hand  is  covered  entirely 
by  a  superfluous  book.  It  is  also  unpardonable  when  the  supporting 
leg  of  a  figure,  which  gives  it  a  hold,  is  hidden  or  partially  hidden  by 
unimportant  accessories  ;  this  is  even  annoying  in  lifeless  objects,  as  a 
table  or  a  pillar.  But  it  does  not  follow  by  any  means  that  all  the 
legs  must  be  absolutely  visible.  For  'instance,  in  Raphael's  "  School 
of  Athens,"  which  is  very  rich  in  figures,  the  covering  of  the  less  im- 
portant figures  by  the  more  prominent  ones  in  the  foreground  is  ex- 
plained by  the  nature  of  the  case. 

(b.)  Arrangements  in  Landscapes  and  Architecture. 

In  photographing  landscapes  we  can  very  seldom  arrange  the  ob- 
ject to  suit  our  desire.  We  can,  however,  obtain  from  the  same  object 
extraordinary  changeable  pictures,  by  changing  the  point  of  view, 
and  awaiting  a  more  favorable  illumination.  The  choice  of  the  point 
of  view  (or  standpoint)  is  the  main  point  in  landscape  photography. 
If  you  visit  a  strange  region  or  quarter  it  is  quite  unnecessary  to  take 
the  camera  along  on  your  first  visit.  Having  chosen  your  object, 
and  convinced  yourself  that  it  would  make  a  good  picture,  study  it 


358  THE  PRACTICE  OF  PHOTOGRAPHY. 

as  a  painter  would  if  he  wants  to  paint  it,  notice  the  best  time  of  the 
day,  visit  the  place  several  times  during  the  day  to  note  in  what 
manner,  in  the  position  of  the  sun,  light  and  shade  changes  the  shape 
of  the  masses.  Very  often  photographers  commit  a  mistake  by 
making  exposure  when  the  sun  is  directly  at  their  back,  i.  e.,  having 
the  sun  in  its  greatest  illumination  ;  they  do  not  consider  that  they 
require  shadow  as  well  as  light.  Some  objects  require  a  lighting 
from  the  side,  while  others  look  better  with  the  sun  back  of  them, 
the  rays  tipping  the  edges  of  the  mountains,  a  building,  or  trees. 
After  the  object  has  been  chosen,  the  standpoint  is  selected.  In  this 
the  camera  can  be  taken  along.  All  objects  not  in  harmony  with 
the  character  of  the  scene  had  better  be  removed ;  often  a  removal 
of  the  standpoint  a  few  steps  will  suffice,  or  raising  or  lowering  the 
apparatus.  Twigs  and  branches  of  trees  in  the  foreground  can  only 
be  removed  by  cutting  away.  An  indifferent  foreground  can  also  be 
cut  away  in  the  finished  picture.  Very  important  here  is  the  choice 
of  lenses ;  lenses  of  short  focus  and  large  field  of  view  (pantoscope, 
wide-angled  aplanatic)  produce  the  foreground  and  the  objects  in  the 
immediate  vicinity  very  large,  whereas  the  distant  objects  are  very 
small  (Fig.  145).  Lenses  of  longer  focus  produce  the  distant  ob- 
jects larger,  without  the  large  foreground  and  objects  in  the  vicinity 


Fig.  144. 


(Fig.  144).  According  to  which  is  the  most  important  to  the  operator, 
the  immediate  vicinity  or  the  distance,  he  will  select  from  the  same 
standpoint  his  lenses  for  long  or  short  focus.  In  the  photographs  of 
the  annexed  pictures  of  the  same  object,  the  one  which  was  taken 
with  the  long  focus  (Fig.  144)  is  the  best,  for  it  shows  the  tower 


POSITION  AND  STANDPOINT. 


359 


large  and  at  a  proper  distance.  The  one  taken  with  a  short  focus 
(Fig.  145)  shows  more  of  the  road  and  the  side-wall  in  the  foreground. 
These  do  not  add  to  the  beauty  of  the  picture ;  the  tower,  however, 
appears  small,  and  looks  aside  of  the  large  foreground  as  though  it 
was  a  half-mile  away.  Parallel  lines  produce  in  landscape  an  equally 


unpleasant  effect  as  in  portraits.  When  the  horizon  is  bordered  with 
a  straight  line,  the  middle  or  the  foreground  should  be  wavy.  This 
is  easily  accomplished  by  a  change  of  the  standpoint,  which  is  neces- 
sary to  produce  a  perspective  view  of  the  foreground.  A  motion  of 
a  few  metres  often  changes  the  lines  of  a  picture  altogether.  The 
front  view  of  an  object  is  seldom  as  picturesque  as  a  perspective. 
Strong  symmetrical  pictures  have  the  same  effect  in  landscapes  and 
architecture  as  in  portraits.  If,  for  instance,  the  nave  of  a  church 
were  taken  from  the  centre  of  the  choir,  such  a  picture  would  be  ob- 
tained. The  exact  repetition  of  the  receding  pillars  on  the  opposite 
side  would  appear  monotonous.  This  is  avoided  by  taking  a  position 
outside  of  the  middle.  The  same  remarks  are  valid  for  innumerable 
cases.  A  lengthy  view  of  a  mall,  a  stream,  or  a  street  must  not  be 
taken  from  the  middle  if  it  can  be  avoided. 

A  picture  must  always  have  a  proper  close.  For  instance,  the 
centre  of  a  vault  or  arch  must  not  be  cut  off  or  left  without  a  sup- 
port; better  close  at  one  of  the  pillars.  The  fancy  of  the  observer 
could  possibly  imagine  the  missing  support ;  it  is,  however,  well  and 
good  to  have  it  actually  represented  in  the  picture.  Doubts  often 
arise  in  what  position  to  place  the  horizon.  The  following  rule  can 
be  applied  :  the  horizon  line  must  not  be  at  equal  distance  from  the 


Fig.  145. 


360 


THE  PRACTICE  OF  PHOTOGRAPHY. 


top  and  lower  part  of  the  picture,  i.  e.,  the  surface  must  not  be  equally 
divided  into  earth  and  sky.  This  can  be  accomplished  by  raising  or 
lowering  the  standpoint  of  the  camera,  or  inclining  towards  the  earth 
or  sky.  It  must  be,  however,  observed  that  perpendicular  lines  run 
together  under  such  circumstances  (see  p.  328).  The  effect  of  the 
heightening  of  the  standpoint  on  the  foreground  has  already  been 
discussed  in  the  article  on  perspective.  The  foreground  must  never 
be  filled  with  anything  to  draw  the  attention  away  from  the  main 
object.  Perfectly  horrible  are  crowding  gapers.  The  sky  is  always 
troublesome  to  the  photographer.  Seldom  a  nice  and  fitting  sky  is 
found  above  a  landscape,  notwithstanding  that  the  representation  of 
natural  clouds  presents  no  mechanical  or  chemical  difficulty.  There 
is  here  nothing  left  but  to  await  a  fitting  sky  ;  take  it  and  print  it  in 
separately,  or  to  sketch  a  sky  on  the  negative  with  lead-pencil  or 
india-ink,  either  on  one  side  or  the  other.  Many  cover  the  whole  of 
the  sky,  so  that  it  does  not  print,  and  then  let  it  color  up  in  the 
light,  so  that  the  horizon  is  the  lightest,  and  the  top  the  darkest. 
For  this  purpose  place  the  print,  print-side  down,  on  a  dull  black 
body,  pick  up  the  sky-side  so  that  the  light  may  strike  it,  and  let 
it  darken. 

CHARACTERISTICS  AND  INDIVIDUALITY. 

We  have  spoken  repeatedly  of  characteristic  features,  motions, 
limbs,  etc.,  and  the  reader  will  ask,  What  are  characteristic  signs  ? 
I  call  all  external  signs  that  are  necessary  to  a  true  and  comprehensive 
representation  characteristic. 

For  a  letter-writer  the  writing  hand  is  of  course  characteristic, 
even  when  it  is  not  in  the  act  of  writing,  but  is  merely  lifted  while 
the  writer  is  in  a  contemplative  mood,  and  the  representation  would 
be  faulty  and  incomprehensible  if  this  hand  were  hidden,  even  if  the 
figure  were  surrounded  by  piles  of  paper  and  rows  of  inkstands  and 
sandboxes.  Sometimes  for  a  clearer  definition  of  the  characteristics 
of  the  subject  other  marks  have  to  be  added.  How,  for  instance, 
could  we  characterize  a  wine-drinker  without  a  glass,  a  gambler 
without  dice  or  cards  ?  Some  people  think  that  they  can  get  along 
with  these  accessories  alone.  We  Irave,  for  instance,  a  representation 
of  young  Bacchus,  with  lifted  and  foaming  champagne-glass,  but 
alas !  the  face  is  cold  and  dry ;  the  model  shows  that  it  is  nothing  but 
a  model,  and  the  features  indicate  that  the  fluid  in  the  glass  is  noth- 
ing but  small  beer. 

Such  a  representation  is  not  only  difficult  to  understand,  but  it  is 
also  untrue.    A  woman  who  folds  her  hands  does  not  pray  unless  the 


CHARACTERISTICS  AND  INDIVIDUALITY. 


361 


expression  of  her  face  indicates  this.  This  holds  good  also  for  ordi- 
nary portrait  representations.  Observe  the  photographic  portrait 
taken  with  top-light  (page  303).  The  fierce-looking  eyes  and  the 
heavy  compressed  lips  are  false  indications,  for  they  indicate  a  tem- 
perament which  the  man  does  not  possess.  Neither  does  the  front 
and  side-light  illumination  give  the  character  of  the  person.  A  great 
artist  needs  very  little  to  indicate  the  character,  but  the  photographer 
often  requires  a  great  deal.  That  is  the  distinction  between  art  and 
photography.  The  painter  pays  attention  to  the  characteristic  points 
only,  while  he  modifies  the  others  or  leaves  them  out  entirely,  and  the 
mechanically  working  photographer  produces  everything,  even  the 
minutest  trifles,  with  equal  distinctness. 

Nearly  every  person  has  his  own  character — i.  e.,  his  own  princi- 
ples of  action  (some,  however,  have  none  whatever).  Some  act  with- 
out any  forethought,  quite  unconcerned  about  the  consequences. 
They  think  lightly  of  even  the  most  serious  things,  and  look  on 
everything  from  the  most  cheerful  standpoint  (optimists),  while  others 
again  look  always  gloomily  into  the  future  (hypochondriacs). 

But  in  a  picture  we  must  represent  the  true  character  of  a  person, 
which  can  be  done  in  a  twofold  manner.  We  either  represent  the 
figure  at  rest  (as  the  statue  of  Lessing),  or  we  represent  it  in  action 
(Luther).  It  has  often  been  said  that  the  portraitist  should  not 
paint  action.  This  is  very  true  ;  but  when  action  contributes  in  such 
a  weighty  manner  to  rendering  the  character  of  the  person,  as  the 
features  in  Rietschel's  Luther  (Fig.  146)  indicate,  our  objections  are 
hushed  in  admiration.  It  seems  as  if  this  man  of  metal,  this  giant 
mind,  thunders  to  every  one  his  "Here  I  stand.  I  cannot  do  other- 
wise.   God  help  me.  Amen." 

When  Luther  here  as  a  hero  stands  divinely  grand  before  us,  we 
must  say  that  this  representation  is  justified,  even  when  we  are  told 
that  he  did  not  wear  the  gown,  but  was  simply  clad  in  the  costume  of 
his  monkish  order,  with  his  head  shaved  according  to  its  regulation, 
and  that  at  that  time  he  was  as  thin  as  a  match.  If  Rietschel  had 
confined  himself  closely  to  these  facts,  he  would  have  represented  an 
Augustine  monk,  but  not  a  Doctor  Luther.  Rietschel  in  his  repre- 
sentation of  Luther  has  departed  from  historical  facts,  but  gained 
largely  in  characteristic  effect. 

The  artist  often  has  to  struggle  long  and  hard  to  find  the  charac- 
teristic representation  of  an  historical  or  mythical  figure.  For  cen- 
turies they  struggle,  and  always  in  vain,  until  at  last  a  god-inspired 
genius  seizes  the  problem  and  solves  it  in  such  a  forcible  and  con- 
vincing manner,  that  the  form  becomes  a  model  and  an  ideal  which 


362 


THE  PRACTICE  OF  PHOTOGRAPHY. 


is  imitated  over  and  over  again,  until  finally  it  becomes  the  type  of 
the  character.  So  the  Zeus  and  the  Athene  by  Phidias,  and  the 
Hercules  by  Lysippus. 


Fig.  146. 


Few  people  have  features  which  clearly  and  unmistakably  repre- 
sent their  character.  Physiognomists  are  badly  at  fault.  I  know 
persons  whose  compressed  lips  have  something  sly  and  malicious, 
whose  small  greenish  eyes  have  something  false  and  treacherous  in 
them,  and  still  they  are  the  best  and  most  amiable  persons,  whose 
character  and  life  are  without  fault  or  blemish.  While,  on  the  other 
hand,  persons  with  open  and  noble  countenances,  who  at  first  sight 


CHARACTERISTICS  AND  INDIVIDUALITY.  363 


will  win  the  confidence  of  every  one,  very  often  prove  to  be  the  greatest 
rascals.  A  great  many  people  run  about  whose  faces  are  living  lies. 
They  enter  the  studio  of  the  photographer  and  he  shall  make  a  pic- 
ture of  them  which  not  only  gives  the  outside  appearance,  the  like- 
ness, but  which  also  indicates  his  character,  which  latter  often  contrasts 
in  the  most  heterogeneous  manner  with  his  outside  appearance.  Few 
persons  are  aware  how  much  belongs  to  the  complete  representation  of 
a  person. 

Some  appear  charming  when  they  talk,  sing,  or  gesticulate.  Some 
represent  themselves  only  to  advantage  when  they  are  in  company, 
with  a  large  circle  around  them  listening  to  their  witticisms.  Some 
are  only  gay  and  lively  in  ladies'  society,  while  others  again  show 
best  in  male  company.  Some  people  appear  dark  and  gloomy  in  the 
room,  while  they  are  lively  and  amiable  in  the  open  air.  The  honest 
countryman  feels  depressed  and  embarrassed  when  he  treads  the  ele- 
gantly carpeted  floor  of  the  richly  furnished  atelier,  but  he  is  happy 
in  his  humble  cot.  All  these  circumstances,  however,  have  their  in- 
fluence on  the  appearance  of  a  person.  The  portrait,  no  matter  how 
good  it  is,  will  only  give  an  extract  of  the  character.  It  may  appear 
a  speaking  likeness  (scarcely  a  singing  one),  but  it  will  only  give 
partial  satisfaction,  as  the  accessories  which  the  original  requires  to 
produce  its  whole  effect  are  wanting.  The  painter,  who  knows  his 
original,  does  not  always  succeed  in  this;  how  much  more  difficult 
must  it  be  for  the  photographer,  who  has  to  represent  a  perfect 
stranger,  who  sometimes  intends  to  leave  in  the  next  train,  and  who 
in  his  whole  behavior  shows  so  much  hurry  that  he  would  make  a 
good  representation  of  Mercury  with  winged  sandals  on  his  feet. 

To  this  we  must  add  the  circumstance  that  a  great  many  do  not 
care  particularly  for  a  true  representation  of  their  character.  The 
rascal  wishes  to  appear  as  an  honest  man ;  the  lady  passing  into  the 
sear  and  yellow  leaf  of  autumn  wants  to  be  young  and  coquettish  ;  the 
servant  girl  wishes  to  represent  the  mistress ;  the  daugher  of  the  me- 
chanic wants  to  look  like  the  court  lady,  and  the  street-sweep  would 
be  a  gentleman.  So  do  their  pictures  serve  them  as  a  gratification  of 
their  personal  vanities ;  and  in  order  that  they  may  appear  very  fine 
and  extraordinary,  they  put  themselves  into  their  own  (and  sometimes 
borrowed)  Sunday  clothing,  which  sits  upon  them  as  uncomfortably  as 
possible.  They  practice  before  the  glass,  consulting  papa  and  mamma, 
wife  or  sweetheart,  on  artistic,  impossible  pose.  Even  educated  per- 
sons have  such  "cranky"  notions.  Thorwaldsen  relates  of  Byron, 
who  visited  him  to  sit  for  his  bust,  that  "he  placed  himself  in  the 


364 


THE  PRACTICE  OF  PHOTOGRAPHY. 


chair,  but  the  moment  I  commenced  to  work  his  features  changed. 
When  I  called  his  attention  to  it,  he  remarked,  '  This  is  the  true  ex- 
pression of  my  face.'  I  made  no  reply,  but  finished  his  portrait  as  I 
saw  proper.  Everybody  declared  my  bust  to  be  a  perfect  likeness 
except  Byron  himself,  who  exclaimed,  '  The  bust  does  not  resemble 
me;  I  look  much  more  unhappy.'  He  wanted  at  that,  time  to  look 
very  unhappy,"  continues  Thorwaldsen. 

The  photographer  is  much  worse  off  than  the  sculptor  or  painter. 
Suppose  Byron  had  gone  to  a  photographer  and  placed  his  woful 
face  before  the  camera.  What  could  the  photographer  have  done  ? 
Unfortunately  he  has  at  the  decisive  moment  to  depend  on  his  model, 
and  how  often  his  model  at  this  critical  moment  disappoints  him,  not 
always  from  ill  will,  but  often  from  nervousness. 

Much  depends  on  the  photographer  himself,  who  should  understand 
how  to  govern  the  public  in  an  amiable  manner,  for  the  treatment  of 
the  public  is  no  unimportant  part  of  photographic  aesthetics. 

Generally  speaking  photography  has  to  represent  objects  in  a  posi- 
tion of  rest,  and  only  occasionally  do  we  find  representations  of  still 
life,  where  the  figures  are  employed  in  a  harmless  activity,  be  it  read- 
ing, writing,  or  contemplating  a  picture,  mechanics  at  work,  musicians 
performing  on  instruments,  or  children  at  play.  In  representing  such 
objects  the  photographer  can  only  seize  a  certain  moment,  and  it  is  of 
the  greatest  importance  to  know  how  to  decide  which  moment  to 
choose.  Not  only  artistic  arrangement  has  to  be  consulted,  but  con- 
tour and  harmony  of  lines  must  be  studied.  Take,  for  instance,  a 
smith  wielding  the  hammer,  or  a  sculptor  with  his  chisel.  He  places 
the  chisel  on  the  block  of  marble,  lifts  the  hammer  above  his  head, 
and  with  a  heavy  stroke  it  descends  on  the  chisel.  It  would  ap- 
pear very  weak  if  we  would  represent  this  last  moment,  when  the 
hammer  touches  the  chisel ;  far  much  truer,  more  lifelike,  and  com- 
prehensible would  it  be  to  place  the  hand  with  the  hammer  above  the 
head  in  the  act  of  striking.  In  the  simplest  motions,  even  in  walk- 
ing, we  observe  similar  deepseated  differences.  Not  every  phase  is 
equally  comprehensible.  Many  no  doubt  have  seen  the  walking 
figures  in  instantaneous  pictures,  where  the  one  leg  is  stretched  for- 
ward in  the  act  of  stepping.  Although  this  motion  is  entirely  natural, 
and  forms  a  part  of  our  motion  in  walking,  still  it  does  not  appear 
characteristic,  but  almost  comical ;  it  rather  gives  the  impression  of  a 
military  exercise. 

Our  walk  is  rather  a  complicated  motion  as  simple  as  it  may  ap- 
pear to  us.    We  step  forward,  the  weight  of  the  body  rests  on  the  for- 


CHARACTERISTICS  AND  INDIVIDUALITY.  365 


ward  foot ;  at  the  same  time  we  ele- 
vate the  heel  of  the  other  foot ;  we 
lift  ourselves  on  the  toes  of  the  rear 
foot,  and  give  the  body  a  push  for- 
ward, which  is  the  real  cause  of  the 
forward  motion.  When  this  has 
been  done,  we  force  the  rear  foot  for- 
ward, and  the  same  thing  is  repeated 
over  again.  Of  all  these  different 
movements,  the  one  which  causes  the 
forward  motion  is  the  most  interest- 
ing— i.  e.,  where  the  toes  of  the  rear 
foot  push  the  body  forward,  while 
the  forward  one  rests  firmly  on  the 
ground  and  supports  the  body.  And 
this  is  the  position  which  artists  select 
in  the  representation  of  walking  fig- 
ures. It  is  on  the  one  hand  the 
most  characteristic,  while  on  the 
other  it  gives  the  firmest  position  to 
the  person  so  represented. 

(See  Thorwaldsen's  Triumphal 
March  of  Alexander,  Fig.  147.)  A 
number  of  walking  figures  are  here 
represented,  and  one  would  have 
supposed  that  for  the  sake  of  variety 
the  artist  would  have  selected  dif- 
ferent phases  of  the  walking  motion, 
and  still  we  see  all  the  figures  in  the 
movement  where  the  rear  foot  is  in 
the  act  of  being  lifted  from  the 
ground.  Something  similar  we  find 
in  Konewka's  Scene  from  Faust. 
Only  the  two  soldiers  have  a  very 
characteristic  and  for  them  suitable 
military  walk,  with  both  feet  stretch- 
ed forward.  Solemn  processions 
characterize  themselves  differently. 
In  the  triumphal  Frescos  of  the 
Parthenon,  the  female  figures  step 
on  both  feet.  It  shows  how  difficult 
it  is  to  characterize  even  simple 
motion  in  the  picture. 


Fig.  147. 


366 


THE  PRACTICE  OF  PHOTOGRAPHY. 


The  characteristic  representation  of  mental  condition  is  still  more 
difficult.  Foerster  calls  attention  to  Bendemann's  Jeremiah.  (Fig. 
148.)  The  intention  was  to  represent  a  person  deeply  grieved ;  but 
the  circumstance  that  the  hand  does  not  support  the  head,  but  simply 
pushes  it  sideways,  gives  to  it  more  the  character  of  an  angry  person, 
or  one  that  suffers  bodily  pain. 

The  same  author  remarks  very  pertinently,  "How  unnatural  the 
picture  of  a  praying  person  would  be  who  would  not  bend  her  head 
downward,  but  hold  it  stiff  and  vertical,  and  where  the  hands  only 
lightly  touch  each  other,  instead  of  being  folded."  Such  figures  re- 
mind one  of  the  coquettish  sinners,  who  go  to  church  as  a  place  of 
rendezvous,  and  who  show  that  they  care  more  for  their  surroundings 


Fig.  148. 


than  for  the  worship  of  God.  Such  studied  positions  are  very  common 
in  the  photographic  representations  of  real  life.  The  models  feel 
their  importance,  and  it  is  very  difficult  to  prevent  them  from  taking 
affected  positions. 

Care  should  be  taken  with  actors  and  actresses,  although  these 
are  very  estimable  models.  On  the  stage  much  can  be  well  excused. 
Even  a  movement,  which  is  not  exactly  beautiful,  does  little  harm,  as 
it  occupies  but  a  few  seconds  of  time ;  but  it  becomes  horrible  when  it 
is  immortalized  in  the  picture.  Pictures  of  "  mimics,"  who,  when, 
they  wish  to  remove  a  glove,  stretch  out  the  arm  as  if  they  were  pull- 
ing the  sword  of  a  giant  from  its  scabbard,  appear  absolutely  ridicu- 
lous. 

Finally,  I  wish  to  call  attention  to  how  much  the  drapery  is  de- 
pendent upon  the  motion.  For  instance,  see  the  person  playing  the 
"  tuba,"  in  Thorwaldsen's  Triumphal  Procession  (Fig.  147).  In  con- 
sequence of  inertia  on  the  one  hand,  and  the  resistance  of  the  air  on 
the  other,  the  garment  in  walking  will  fly  backward. 


CHARACTERISTICS   AND  INDIVIDUALITY. 


367 


We  find  something  similar  in  the  modern  costume.  Nothing  shows 
more  untruth  than  a  photograph  of  figures  apparently  in  motion  where 
the  drapery  hangs  down  to  the  body.  Such  motions,  which  to  char- 
acterize them  require  flowing  draperies,  are  not  suited  for  photographic 
representations.  When  the  photographer  wishes  to  represent  motion, 
he  should  choose  close-fitting  garments  for  his  figures.  This  is  the 
reason  why  the  photographs  of  mimic  artists  or  ballet  dancers  appear 
in  a  measure  dead-like  and  rigid,  when  it  is  intended  to  represent  them 
in  action. 

But  whatever  may  be  chosen  in  order  to  give  character  to  the  ob- 
ject, everything  that  is  not  in  itself  beautiful  should  be  avoided.  The 
antique  artists  have  never  represented  a  fury,  says  Lessing,  and  the 
head  of  the  Medusa,  whose  horrid  countenance  was  to  turn  everything 
into  stone,  looks  yet  beautiful. 

The  beautiful  cannot  be  learned  by  heart,  as  a  rule  in  arithmetic. 
The  feeling  for  it  is  a  natural  gift,  and  study  can  only  develop  it.  It 
cannot  create  it.  There  are  plenty  of  photographers  whom  nature 
has  sadly  neglected  in  this  respect.  They  may  learn  at  least  what 
they  will  have  to  avoid,  from  what  I  have  said,  and  when  they  feel 
that  they  cannot  create,  themselves,  they  should  take  examples  of  ac- 
knowledged value  as  their  patterns. 

While  the  mental  peculiarities  of  a  person  are  compounded  together 
in  character,  individuality  is  understood  to  be  their  bodily  peculiari- 
ties. There  are  certain  proportions  of  the  height  and  breadth  of 
body,  size  of  head,  size  of  mouth  and  eyes,  which  make  the  pleasant- 
est  impression,  proportions  which  for  artists  have  by  long  study  be- 
come standard,  which  are  called  normal,  which  in  fact  seldom  occur. 
The  deviations  from  the  normal  proportions  make  up  the  individual 
difference.  One  has  a  somewhat  longer  nose,  a  larger  mouth,  closer- 
placed  eyes  than  another.  Every  individual  shows  such  deviations, 
some  more,  others  less.  We  must  here  remark,  that  that  which  in 
ordinary  life  is  called  beautiful,  often  does  not  show  the  least  trace 
of  those  beautiful  proportions  admired  by  artists,  which  on  the  one 
part  is  based  on  masses,  on  the  other  in  noble  lines  and  outlines. 
What  the  novice  calls  beautiful  can  rather  be  called  pleasing  or 
pretty.  Girls  that  pass  as  beautiful  often  have  striking  dispropor- 
tions, which  the  untutored  eye  of  the  novice  overlooks  very  easily  in 
judging.  The  charm  of  a  so-called  beautiful  face  often  lies,  not  in 
the  form,  but  in  the  color  of  the  cheeks,  eyes,  and  hair,  the  grace 
and  vivacious  exchange  of  looks,  the  roguish  smile  of  the  mouth 
and  eyes.  All  this  has  nothing  to  do  with  a  beautiful  form,  and  as 
such  charms  as  do  not  lie  in  the  form  are  often  very  hard  to  re- 


368 


THE  PRACTICE  OF  PHOTOGRAPHY. 


produce  by  the  photographer  by  such  models,  he  has  trouble.  Petsch 
says:*  "With  a  normal  person,  i.  e.,  with  one  that  is  bodily  and  men- 
tally well  formed,  we  will  have  little  trouble.  The  picture  will  be  set 
up  by  novices  as  a  pattern  for  us,  even  if  it  is  not  a  technical  success. 
The  very  smallest  number  of  them  are  normal,  nearly  all  have  some 
defects,  not  beautiful,  bodily  as  well  as  in  their  behavior,  and  these 
peculiarities  are  those  which  cause  us  so  much  annoyance,  and  in 
many  cases  failure.  We  are  certainly  not  in  the  wrong  if  we  excuse 
these  shortcomings.  Surely  it  is  more  ingenuous  to  say,  '  Be  as  ugly 
as  you  may,  my  art  shall  show  what  can  yet  be  made  of  you.'  "  It 
is  very  easy  to  explain  why  blondes  appear  to  be  slighted.  Their 
charm  lies  often  in  their  color,  in  which,  in  nature,  the  irregularity  of 
feature  and  homely  form  are  overlooked,  and  these  are  just  what  are 
retained  in  photography.  Deformity  and  ugliness  of  figure  is,  alas, 
in  a  greater  or  smaller  degree,  the  object  of  our  daily  study.  Crooked 
persons  we  shall  make  straight,  stout  ones  slim,  thin  ones  stout,  etc. 
To  be  brief,  all  infirmities  shall  be  covered  up  and  silenced.  To  at- 
tain this  we  must  above  all  be  assured  of  perfect  freedom  in  regard 
to  the  position  and  the  style  of  the  picture.  Herewith  much  is  accom- 
plished ;  bust  pictures  are  mostly  recommended  in  an  ugly  figure,  if 
the  head  is  interesting  enough  to  take  exclusively.  If  this  is  not 
the  case,  another  method  must  be  tried.  A  very  stout  person  I  would 
take  standing,  from  the  knee,  cutting  the  figure  off  pretty  low;  this 
will  make  it  appear  more  slim ;  a  slim  one  in  the  opposite  manner. 
By  buttoning  or  unbuttoning  the  coat,  similar  effects  are  attained, 
also  in  the  color  of  the  dress.  Black  appears  tall  and  slim,  white 
stout.  With  decorations,  there  is  also  much  effected.  On  the  person 
itself,  with  lace,  handkerchiefs,  cloaks,  etc.,  much  can  be  covered, 
and  the  attention  drawn  off  by  fine  arrangement  of  the  background, 
and  the  whole  made  to  appear  interesting.  If  in  this  style  of  pic- 
ture, the  head  has  a  less  unassuming  effect,  it  is  generally  the  case  in 
large  heads,  which  take  up  all  the  room  on  the  card.  These  are  only 
suitable  for  wholly  normal  or  very  interesting  heads.  Even  then  it 
must  be  decorated  with  secondary  work,  and  very  effectively  illumi- 
nated. Many  irregularities  of  the  head  can,  by  a  dexterous  use  of  the 
proportions,  be  equalized.  Of  all,  crooked  noses  occur  the  most  fre- 
quently. Such  are  the  most  striking  in  a  front  view ;  this,  of  course, 
should  be  avoided.  Take  the  head  from  the  side  showing  the  small- 
est surface  of  the  nose,  so  that  the  larger  will  be  in  the  shadow. 
Almost  as  annoying  is  a  crooked  mouth,  i.  e.}  such  a  one  that  is  not 


Photograph.  Mittheil.,  vol.  7,  p.  138. 


CHARACTERISTICS  AND  INDIVIDUALITY.  369 


parallel  with  the  intersection  line  of  the  eyes.  The  rule  here  is,  even 
in  profile,  to  take  the  side  with  the  highest  part,  bringing  the  lowest 
.  in  the  shortening.  In  crossed  eyes  there  is  no  alternative  but  to  take 
the  head  profile.  The  arrangement  of  the  hair  is  of  the  greatest  im- 
portance, especially  with  ladies ;  very  few  understand  the  styles  that 
suit  the  shape  of  their  head.  They  follow  the  fashion  blindly,  all  the 
same  whether  they  have  long  or  short  necks,  broad  or  narrow  faces. 
Here  it  is  the  place  of  the  photographer  to  advise,  if  necessitated,  to 
step  in  and  aid  himself.  A  broad  face  appears  with  hair  arranged 
sideways  or  deep  still  broader.  A  too  long  neck,  with  high  stuck 
hair  looks  horribly  thin,  while  a  few  falling  locks  would  cover  the 
defect.  A  high  forehead,  in  males  a  mark  of  beauty,  is  in  females  the 
opposite.  Many  ladies  can  skilfully  cover  this  with  short  locks  or 
curls. 

In  a  profile  picture  it  must  be  observed,  that  the  back  part  of  the 
head  does  not  appear  too  flat  by  the  insufficient  hair,  or  being  pressed 
too  smooth ;  a  little  loosening  will  obviate  it.  Ladies  with  a  short 
neck  must  not  make  it  shorter  with  high  standing  frills  or  ribbons ; 
for  ladies  with  short  waists,  short  jackets  are  recommended,  which 
make  the  waist  appear  longer.  Short  figures  appear  still  shorter  with 
a  trailing  dress.  The  hands  are  next  to  the  head  in  importance.  They 
are  the  cliff  on  which  the  beauty  of  many  pictures  are  wrecked.  The 
effect  of  large  and  ugly  hands  must  be  overcome  by  taking  a  bust,  or 
if  this  cannot  be  done,  improve  and  reduce  them  by  the  position. 
This  is  done  by  crossing  the  arms,  placing  them  under  the  coat,  or 
lapel,  or  making  a  shortened  view. 

We  have  seen  in  all  these  cases,  that  opposed  to  outward  peculiari- 
ties, there  is  a  remedy  or  at  least  alleviation.  It  is  more  difficult, 
however,  to  master  the  obstacles  which  are  produced  by  the  natural 
mental  peculiarities  of  the  model.  One  of  the  greatest  inconveni- 
ences is  the  impossibility  of  keeping  quiet  during  the  exposure. 
Never  be  persuaded  to  take  a  picture  without  a  head-rest.  Place 
them  in  a  very  simple  sitting  position,  with  a  full  opening  very  short. 
A  second  obstacle  which  frequently  makes  its  appearance  is  stiffness, 
awkwardness,  a  spasmodic  holding  of  the  limbs.  Persons  affected 
with  this  peculiarity  must  be  made  to  understand  above  all  things 
that  the  necessary  quiet  is  not  obtained  by  straining,  but  by  easy 
leaving  themselves  go.  In  the  awkward,  nothing  particular  should 
be  attempted,  but  leave  them  rest  somewhere  in  a  model  position,  in 
which,  as  is  known,  every  one  can  place  himself  at  once  very  easily. 
Embarrassment  is  dispelled  by  a  quiet,  friendly  demeanor,  some 
humor,  and  the  admission  of  a  friend  in  the  operating-room.    A  cer- 

24 


370 


THE  PRACTICE  OF  PHOTOGRAPHY. 


tain  class  of  persons  are  very  unpleasant,  who,  while  sitting,  think  of 
this  and  that,  and  then  commence  pulling  the  cuffs  out  a  little,  fix 
this  pleat,  look  at  their  boots.  Of  course  from  each  of  these  movements, 
that  attained  in  the  position  is  spoiled,  and  it  begins  anew  the  mo- 
ment the  plate  is  ready,  and  the  exposure  should  commence.  For 
such  mistrusting  behavior,  beware  of  getting  angry,  but  make  them 
previously  understand  that  not  only  during  the  time  of  exposure,  but 
for  the  whole  sitting,  they  must  keep  quiet.  We  are  often  asked 
why  the  pictures  of  actresses  are  so  much  better  than  the  ordinary 
citizen  public.  It  is  not  the  greater  beauty  of  these  persons  that  pro- 
duces this  advantage.  They  bring  us  a  selection  of  toilet  articles, 
flowers,  curls,  even  plaids,  and  allow  us  to  arrange  them,  and  deco- 
rate them,  according  to  our  fancy,  to  heighten  the  beauties  and  cover 
the  defects.  How  different  it  is  with  our  good-natured  public.  As 
they  show  themselves  daily  in  a  very  tiresome  dress,  they  want  to  be 
photographed.  If  you  wish  to  add  a  piece  of  stuff  for  decorating,  aye, 
even  to  change  the  position  of  a  curl,  they  will  at  once  remark  that 
does  not  suit  them,  or  they  do  not  wear  them.  Besides,  many  have 
not  the  ease  of  motion,  or  understand  our  intention,  through  which 
the  actresses  aid  us  materially.  Instead  of  being  employed,  in  an 
artistic  and  technical  relation,  in  doing  our  part,  the  most  of  the  time 
is  used  to  conquer  the  peculiarity  of  our  model.  We  have  seen  how 
difficult  it  is  to  overcome  all  these  obstacles  in  the  short  time  of  tak- 
ing a  picture.  The  portrait  photographer  must  possess  not  only  ar- 
tistic and  technical  knowledge,  but  also  the  art  of  intercourse  and 
sociability. 

THE  TREATMENT  OF  THE  PUBLIC. 

Many  persons  have  a  great  aversion  to  being  photographed.  They 
compare  it  with  a  visit  to  the  dentist  or  the  barber,  and  many  a  one 
would  much  rather  be  for  half  an  hour  under  the  hands  of  the  latter 
than  under  the  care  of  the  photographer.  It  frequently  happens  that 
a  person  will  resist  the  importunities  of  his  friends  for  years,  and 
finally  walk  to  the  gallery  like  unto  a  place  of  execution.  Others, 
and  to  this  class  the  ladies  belong  in  particular,  have  no  such  strong 
aversions,  but  they  are  timid  and  nervous  when  they  enter  a  glass- 
house, and  are  not  in  a  condition  to  make  a  good  picture.  Nervous- 
ness is  by  no  means  confined  to  the  handsome  sex,  or  to  the  old  and 
feeble.  Young  and  strong  men  get  sudden  attacks  before  the  camera, 
and  brave  officers  and  soldiers,  who  would  steadily  march  up  to  the 
cannon's  mouth,  will  tremble  before  the  photographic  lens.  They  can 
no  more  stand  still  than  any  one  else. 


THE  TREATMENT  OF  THE  PUBLIC. 


371 


As  this  feeling  is  so  widespread,  the  artist  should  attempt  to  dissi- 
pate it,  and  try  to  make  things  pleasant  to  his  customers.  The  few 
introductory  remarks  on  the  arrival  of  a  visitor  he  should  try  to  make 
as  agreeable  as  possible ;  neither  too  familiar  nor  too  humble,  but  in 
the  light  and  easy  manner  of  the  gentleman.  During  the  prepara- 
tion the  same  easy  and  polite  manner  should  be  maintained. 

Under  such  a  treatment  many  persons  will  lose  their  nervousness, 
and  instead  of  having  an  aversion  to  the  operation,  it  will  afford  them 
pleasure.  This  shows  itself  in  the  pleasant  expression  of  the  portrait, 
and  in  the  carriage  and  quietness  of  the  original. 

It  is  probable  that  many  photographers  have  never  thought  of  the 
importance  of  such  a  treatment,  and  they  must  blame  themselves  if 
people  do  not  like  to  visit  their  establishments.  A  rough  and  violent 
or  impolite  and  affected  manner,  we  frequently  meet  with  among  our 
colleagues.  Many  photographers  will  call  out,  when  everything  is 
ready,  "  Please  look  at  this  point ;  but  make  a  little  more  amiable 
face."  A  lady  will  not  be  pleased  with  such  an  expression,  for  it  in- 
dicates that  so  far  she  has  not  looked  amiable,  and  after  so  polite  a  re- 
quest she  will  not  look  any  better.  " Not  quite  so  serious,"  would  be 
less  offensive.    Much  also  depends  on  the  manner  in  which  it  is  said. 

Another  point  which  severely  tries  the  patience  and  good  humor  of 
the  photographer  is  the  head-rest. 

His  sitters,  almost  without  exception,  misunderstand  this  object, 
and  dislike  it.  But  head-rests  are  necessary,  and  it  requires  tact,  firm- 
ness, and  good  humor  in  insisting  on  their  use.  The  general  remark 
is,  "  I  will  look  better  without  it.  It  only  makes  me  look  stiff."  The 
best  answer  would  be,  "  You  may  perhaps  feel  stiff,  but  you  will  not 
look  so  in  the  picture."  It  is  the  general  custom  to  request  the  per- 
son to  look  steadily  at  a  certain  point,  and  it  gives  a  calm  expression 
to  the  whole  face. 

Sometimes,  and  particularly  during  a  long  exposure,  the  expres- 
sion will  change  during  the  thirty  or  forty  seconds  of  time,  and  pass 
from  a  pleasant  smile  to  a  melancholy  look.  Many  a  photographer 
opens  his  lens  on  a  laughing  seraphim  and  closes  it  on  a  fallen  angel. 
It  is,  hence,  necessary  to  caution  the  sitter  against  changing  his  ex- 
pression. The  corners  of  the  mouth  are  particularly  liable  to  this 
change. 

Sometimes  people  will  insist  on  having  their  pictures  taken  in  un- 
favorable weather.  They  demand  a  trial,  although  the  photographer 
feels  perfectly  convinced  that  it  is  but  a  loss  of  time  and  useless,  and 
that  success  is  impossible. 

The  photographer  should  remind  such  persons  that  it  is  in  their 


372. 


THE  PRACTICE  OF  PHOTOGRAPHY. 


own  interest  to  postpone  the  sitting,  that  it  would  only  give  them 
unnecessary  trouble,  and  that  he  has  no  selfish  motive  in  making  the 
request.  Some  people  will  bring  a  friend  along,  who  wants  to  repre- 
sent the  artist?,  and  assist  in  arranging  the  sitter.  A  young  lady,  for 
instance,  will  be  accompanied  by  a  young  gentleman — a  brother  per- 
haps ;  perhaps  somebody  still  dearer — to  whose  judgment  she  appeals 
while  the  photographer  places  her  in  the  proper  position.  The  young 
friend  commences  to  give  advice  how  and  in  what  direction  his  pro- 
tegee is  to  look,  generally  requesting  her  to  look  steadily  at  a  given 
point  long  before  the  photographer  is  ready.  To  a  good  photographer 
such  an  interference  is  unbearable.  He  finds  his  presence  ignored, 
his  place  usurped  by  another,  and  feels  that  no  confidence  is  placed 
in  his  artistic  feeling  nor  in  his  skill.  Here  it  is  necessary  to  main- 
tain your  position,  and  to  declare  in  a  firm,  collected,  and  polite  man- 
ner, that  either  the  photographer  or  the  friend  must  withdraw.  That 
a  division  of  labor  is  not  admissible,  and  if  the  gentleman  wishes  to 
make  the  arrangement,  he  may  do  so,  but  the  photographer  will  not 
answer  for  the  result.  This  has  generally  the  desired  effect,  and  the 
friend,  who  perhaps  never  intended  to  become  intrusive,  will  generally 
withdraw. 

Occasionally  some  one  will  insist  quite  obstinately  that  he  wishes 
to  be  taken  in  a  "  comfortable  "  position.  People  often  think  that 
everything  which  is  comfortable  must  be  naturally  graceful  and  beau- 
tiful.. They  throw  themselves  into  the  chair  in  a  position  which  on 
the  picture  would  give  to  them  the  legs  of  an  elephant  and  the  head 
of  a  dwarf.  When  such  people  are  stubborn,  it  is  best  to  let  them 
have  their  own  way.    They  will  not  try  it  a  second  time. 

With  all  these  trials  and  vexations  to  which  the  whims  of  the  pub- 
1  lie  expose  the  artist,  it  is  not  always  easy  to  keep  an  even  temper, 
and  still  he  has  to  do  it  for  his  own  sake  and  for  the  sake  of  his  cus- 
tomers. It  is  not  surprising  that  sometimes  the  stupidity  of  his 
clients  puts  him  in  a  bad  humor,  for  there  are  occasionally  extremely 
provoking  cases.  A  lady,  for  instance,  will  return  her  cards  without 
stating  any  reason,  and  after  repeated  inquiries  she  will  state  that  she 
does  not  like  the  position  of  her  hat,  or  that  a  curl  should  fall  forward 
instead  of  backward ;  another  will  complain  of  the  position  in  which 
she  has  been  taken,  and  threatens  to  bring  her  husband  along  the  next 
time  for  the  sake  of  keeping  control. 

Another  unpleasant  kind  of  customers  are  those  who  want  to  be 
photographed  with  small  dogs  on  their  laps,  or  large  ones  by  their 
side ;  but  worst  of  all  are  small  children.  These  little  screamers  are 
generally  accompanied  by  papa,  mamma,  and  nurse,,  who  all  come  to 


THE  TREATMENT  OP  THE  PUBLIC. 


373 


"  help  "  the  photographer.  The  scenes  which  at  such  times  happen 
in  the  atelier  would  be  amusing  if  we  would  not  lose  our  patience. 

It  is  very  necessary  not  to  keep  our  patrons  waiting  too  long  if  we 
desire  to  keep  them  in  a  good  humor. 

Waiting  under  any  circumstances  is  a  tiresome  business,  and  many 
a  picture  shows  but  too  plainly  the  long  waiting  to  which  the  model 
has  been  obliged  to  submit 

Any  one  who  has  a  flourishing  business  will  do  well  to  make  an 
appointment  with  his  patrons  beforehand.  Care  should  then  be  taken 
that  everything  is  in  readiness.  Whoever  commences  to  make  the 
developer  or  even  the  silver-bath  when  the  public  is  waiting  will  soon 
lose  his  custom. 

Messrs.  Loescher  &  Petsch  prepare  the  plate  the  moment  the  model 
enters  the  atelier  (the  arrangements  about  the  style  of  the  picture 
having  been  fixed  beforehand  in  the  reception-room). 

In  the  few  moments  of  conversation  which  precede  the  taking  of 
the  picture,  the  photographer  should  have  sufficiently  examined  his 
model  and  formed  his  conclusions  about  position,  illumination,  ar- 
rangement of  dress,  background,  and  accessories.  He  must  at  once 
arrange  the  pose  while  his  assistant  arranges  the  camera  and  brings 
the  lens  in  focus.  Only  when  the  plate  is  ready  the  rest  should  be 
gently  adapted  to  the  head  (not  the  reverse).  With  a  quick  glance 
the  whole  arrangement  should  be  examined  to  see  if  illumination, 
outline,  drapery,  and  background  form  a  harmonious  ensemble,  and 
then  the  work  should  proceed  at  once  without  delay. 

Any  third  party,  or  any  noise  in  the  adjacent  rooms,  running  to 
and  fro,  etc.,  is  an  annoyance. 

It  is  inconsiderate  in  the  extreme  to  place  the  person  in  the  head- 
rest, and  to  let  him  wait  for  the  plate,  or  to  lose  half  an  hour  in 
making  the  proper  arrangement,  and  to  change  the  position  over  and 
over  again.  The  person  will  feel  that  the  photographer  does  not 
know  exactly  what  he  is  about,  and  will  lose  confidence. 

Children  should  be  taken  very  quickly.  Success  with  them  is  in  a 
measure  a  matter  of  chance.  The  light  should  be  strong,  the  lens 
should  work  rapidly,  and  while  the  artist  draws  the  attention  of  the 
little  one  by  showing  a  toy  or  some  bright  object,  the  assistant  should 
remove  the  cap  the  moment  the  child  sits  quiet. 

Any  one  who  has  much  intercourse  with  children  will  soon  learn 
their  little  peculiarities,  and  by  adapting  himself  to  them  he  gains 
their  affection,  and  they  willingly  obey  his  arrangements.  This  is 
the  reason  why  a  friend  of  children  like  Mr.  Petsch  is  so  successful 
with  them. 


374 


THE  PRACTICE  OF  PHOTOGRAPHY. 


FILLING  THE  PICTUKE. 
ACCESSORIES  AND  BACKGROUNDS. 

In  photographic  practice  certain  sizes  have  become  standard,  and 
they  are  ordered  over  and  over  again.  Particularly  is  this  the  case 
with  the  carte  de  visite  size,  and  also  the  cabinet  size.  Both  these 
sizes  are  dependent  on  the  lens  and  plate-holder  of  the  camera.  The 
photographer  has  to  see  to  it  that  the  space  is  properly  filled. 

When,  in  1858,  Disderi,  in  Paris,  invented  the  carte  de  visite,  and 
by  it  gave  an  enormous  impulse  to  photography,  he  recommended  to 
take  full-length  pictures  as  being  artistically  most  justifiable,  as 
figure  and  deportment  are  necessary  to  the  characteristic  of  an  indi- 
vidual. 

Photographers  generally  made  whole-length  figures  in  the  begin- 
ning, and  only  here  and  there  a  bust  or  f  size  would  make  its  ap- 
pearance. It  did  not  take  a  great  while,  however,  and  busts  became 
more  and  more  in  vogue.  The  public  liked  them.  The  reason  is 
obvious.  A  picture  in  which  only  the  head  and  chest  are  visible 
cannot  be  spoiled  by  a  faulty  arrangement  of  legs  and  arms,  nor  by 
an  ugly  arrangement  of  accessories,  as  too  often  happens  with  full- 
length  pictures.  So  far  as  the  aesthetic  element  is  concerned,  their 
production  is  easier  and  surer. 

To  this  must  be  added  other  advantages.  The  larger  dimensions 
and  the  greater  prominence  given  to  the  most  characteristic  part  of 
the  human  body,  the  head.  Delicate  details  in  the  features,  which 
in  the  small  full-length  picture  were  only  visible  with  a  magnifying 
glass,  become  strongly  marked  (sometimes  too  much  so)  in  the  bust 
picture  or  vignette. 

On  the  other  hand,  individual  shortcomings  and  faults  in  the  illu- 
mination, which  would  scarcely  be  noticed  in  the  full-length  picture, 
became  quite  apparent,  and  it  was  reserved  to  a  later  period  to  re- 
move them. 

Since  this  size  has  become  quite  fashionable,  various  experiments 
or  improvements  have  been  attempted  by  enterprising  photographers, 
which  have  gained  a  more  or  less  general  approval  of  the  public. 
At  first,  heads  of  a  size  from  f  to  1  inch,  and  where  more  or  less  of 
the  bust  was  visible,  were  all  that  was  ventured.  Soon  the  size  of  the 
head  was  increased  to  1^  and  2  inches,  apparently  at  first  in  England, 
for  the  first  cards  of  this  kind  which  came  into  my  possession  were 
portraits  of  Boz  (Dickens). 

Although  many  objections  might  be  urged  against  the  adoption  of 


ACCESSORIES  AND  BACKGROUNDS. 


375 


this  size,  still  it  has  become  more  and  more  popular.  I  cannot  help 
statiDg  though  that  it  is  less  suitable  for  the  general  public  than  for  the 
heads  of  the  ladies  of  the  stage,  with  their  rococo  style  of  hair-fixings. 

No  doubt  the  unusual  size  of  the  head  will  show  a  richness  of 
detail,  as  buckles,  chains,  chignons,  curls,  etc.  But  on  the  other 
hand,  the  danger  is  obvious  that  some  undesirable  details,  as  wrinkles, 
freckles,  etc.,  become  unpleasantly  prominent  in  the  picture. 

The  ladies  of  the  stage  have  other  means  at  their  command  to 
cover  such  shortcomings.  They  are  in  reality  the  inventors  of  a 
third  kind  of  retouch,  which,  to  distinguish  it  from  positive  or  nega- 
tive retouch,  we  have  called  the  original  retouch,  as  it  is  with  paint, 
poudre  de  riz,  and  rouge,  applied  on  the  person  itself,  and  at.  present 
this  kind  of  retouch  is  in  many  of  the  Berlin  ateliers  (not  only  by 
ladies  of  the  stage)  practiced  with  good  success. 

With  these  large  heads  a  careful  study  of  illumination  is  of  great 
importance.  To  this  we  must  add  negative  retouching,  which  for 
obvious  reasons  becomes  oftener  necessary  than  in  pictures  of  smaller 
dimensions,  not  to  speak  of  removing  spots. 

Still  another  important  element  is  the  lens  with  which  the  picture 
is  to  be  taken.  On  this  point  we  have  already  given  some  directions. 
For  thick  faces  use  short-focussed  lenses,  and  incline  the  camera 
slightly,  so  that  the  head  will  not  be  exactly  in  the  centre.  Slim 
faces  are  taken  better  in  the  middle  of  the  ground-glass,  with  a  long- 
focussed  lens. 

For  the  general  photographer  bust  pictures  without  a  background 
(vignetted)  are  doubtless  the  most  convenient.  Legs  are  excluded, 
and  generally  the  hands  also.  He  has  no  difficulty  with  the  position 
of  these  extremities.  He  should  pay  the  most  careful  attention  to 
the  head  and  chest,  the  upper  parts  of  the  arms,  a  pyramidal  ar- 
rangement, and  outlines.  The  figure  itself  is  generally  seated,  being 
more  steady  than  the  slightly  vibrating  standing  figure.  The  back- 
ground should  offer  sufficient  contrast  that  the  outlines  may  not  run 
together,  but  stand  out  boldly.  For  black  hair  there  should  be  a 
somewhat  lighter  background,  and  for  light  hair  a  somewhat  darker 
one:* 

*  It  is  certainly  remarkable  that  the  glaring  white  background  in  vign- 
etted pictures  does  not  offend  our  feelings,  while  otherwise  we  are  horrified  at 
every  high-light  in  pictures  with  a  full  background.  We  can  only  explain 
this  by  the  circumstance  that  our  aesthetic  feeling  does  not  consider  the  white 
background  as  belonging  to  the  picture.  It  appears  to  us  as  a  part  of  the 
white  paper,  but  not  as  an  organic  part  of  the  picture.  It  is  quite  different 
with  full  backgrounds  with  designs  on  them.  They  pretend  to  belong  to  the 
picture,  and  are  judged  as  parts  of  the  same. 


376 


THE  PRACTICE  OF  PHOTOGRAPHY. 


Lately,  instead  of  the  white  graduated  backgrounds,  gradated 
ones  and  even  black  ones  have  been  introduced — i.  e.,  the  so-called 
Kembrandt  backgrounds. 

Mr.  Kurtz  and  Mr.  Baker  have  made  the  start,  and  I  have  seen 
pictures  made  by  them  in  which  almost  the  whole  face  is  kept  in  a 
half  shadow,  and  where  the  eye,  contrary  to  the  generally  adopted 
and  recommended  usage,  turns  towards  the  light  instead  of  the 
darker  side,  and  this  style  is  now  quite  general  in  America.  Mr. 
Milster  and  Mr.  Petsch,  in  Berlin,  have  likewise  adopted  this  mode 
of  illumination,  but  they  employ  a  light  background,  and  in  so  far 
they  differ  from  the  "  Rembrandts."  The  following  sketch  by  Mr. 
Grasshoff  will  explain  the  mode  of  making  them. 

A  is  the  apparatus,  P  the  person,  H  the  background.  The  man- 
agement of  the  side  and  top  curtains  is  plainly  visible  in  the  cut. 
The  illumination  must,  as  Mr.  Grasshoff  distinctly  states,  vary  with 
the  person ;  accordingly  more  or  less  curtains  are  opened  or  closed, 


Fig.  149. 


and  the  camera  is  moved  more  to  the  right  or  left,  as  shown  in  the 
ground  plan  (Fig.  149). 

Special  effort  should  be  made  to  have  the  shadows  well  lit  up.  It 
might  be  said  with  much  propriety  that  nature  is  not  as  black  as 
shown  in  the  "  Rembrandt."  This  is  very  true ;  but  we  may  say  with 
the  same  propriety,  that  nature  is  not  as  white  as  represented  in  the 
toned  pictures.  However,  the  brown  foundation  as  background  to 
the  picture  has  already  in  antique  painting  (Pompeii  and  Rome) 
done  good  service,  which  in  modern  times  has  been  happily  imitated. 

Our  modern  painters  too  have  monotonous,  half-dark  surfaces  with- 
out any  design,  as  backgrounds,  only  they  treat  them  differently  from 
most  photographers.  They  appear  unequally  illuminated,  dark  on 
the  one  side  from  whence  the  light  proceeds,  and  light  on  the  side  of 


ACCESSORIES  AND  BACKGROUNDS. 


377 


the  shadows,  and  this  is  why  the  figure  itself  is  plastically  relieved 
from  the  background. 

Such  unequally  toned  backgrounds  are  obtained  by  shading  them 
with  some  object,  which  is  visible  or  not  in  the  picture. 


Fig.  150. 


Loescher  &  Petsch  use  for  this  purpose  a  small  narrow  curtain  g 
(Fig.  150),  which  can  be.  pushed  to  and  fro  on  the  iron  rod,  T  T.  This 

Fip.  151. 


iron  rod  is  hung  at  q,  but  can  be  moved  on  another,  p  p,  so  that  it  can 
be  moved  nearer  or  further  from  the  background.  The  nearer  the 
harder,  the  further  the  softer  is  the  shadow. 


378 


THE   PRACTICE  OF  PHOTOGRAPHY. 


Attention  should  be  paid  that  the  shadow  be  cast  in  such  a  manner 
that  the  illuminated  side  of  the  model  is  cast  upon  it,  while  the  back- 
ground behind  the  shadow  side  of  the  same  remains  light. 

Adam  Salomon,  in  order  to  obtain  the  same  result,  inclines  his 
background,  i.  e.,  he  stands  it  obliquely,  as  in  Fig.  151 ;  the  left  side 
will  be  light,  and  the  right  dark. 

Finally,  we  can  effect  the  same  result  by  raising,  next  to  the  person, 
P,  a  single  curtain,  0  0  (Fig.  152).  The  different  parts  of  the  back- 
ground, H,  appear  unequally  illuminated,  b,  for  instance,  although 
the  glass  side  is  nearer  to  it,  appears  darker  than  a,  as  is  explained  by 
the  angles  of  light  indicated  in  the  figure.  It  is  easy,  by  placing  the 
apparatus  J.  in  a  suitable  position,  to  obtain  the  desired  result.  In 
order  to  light  the  shadows  properly,  a  considerable  quantity  of  front- 
light  is  necessary. 


Fig.  152. 


An  excellent  medium  to  produce  a  background,  being  light  on  the 
shadow  and  dark  on  the  light  side,  is  the  funnel-shaped  background 
of  the  celebrated  photographer,  Kurtz,  in  New  York.  This  is  round, 
of  a  funnel  shape,  about  four  feet  broad  (H,  Fig.  153,  and  Fig.  155, 
A  and  B),  being  two  and  a  half  feet  deeper  in  the  middle  than  at  the 
rim.  This  background  properly  set  produces  the  desired  gradations 
from  light  to  dark.*    A  cylindrical  background  works  similarly. 

*  The  other  pieces  of  Fig.  153,  are  a  reflector  with  two  wings,  F/  F//,  and 
an  opening,  o  R,  through  which  the  camera  points,  and  which  is  very  effec- 
tive in  u  Kembrandts  ;"  further,  a  movable  platform,  P,  on  which  the  sitter  is 
placed.  This  platform  will  allow  the  placing  of  the  sitter  in  any  desirable 
position  (profile,  half  or  three-quarter  face),  without  rising.  Fig.  154  shows 
the  position  of  the  reflector,  R,  the  person,  P,  and  the  background,  H,  in  tak- 
ing of  "  Kembrandts." 


ACCESSORIES  AND  BACKGROUNDS. 


379 


Lately  a  background  has  been  introduced  to  the  trade  by  Bigelow, 
which  has  the  different  gradations  of  light  painted  on  it,  which  can  be 
turned  to  place  the  light  side  wherever  desired. 


Fig.  153. 


With  bust  pictures  it  will  seldom  be  necessary  to  bring  in  other 
objects  than  the  individual.    It  alone  will  fill  the  space,  even  if  the 

Fig.  154.  Fig.  155. 


whole  background  should  be  printed  in  without  any  effort  at  vignet- 
ting. 

It  is  different  with  three-quarter  size  or  whole-length  pictures,  or 
when  the  body  is  in  a  sitting  posture,  or  when  it  supports  itself ;  then 
a  pedestal  or  a  stand  is  necessary,  and  we  also  require  a  floor.  Even 
in  such  cases  we  do  not  hesitate  to  employ  a  monotonous  background, 
and  the  care  of  the  artist  is  confined  to  the  chair,  the  floor,  or  the  sup- 
port (the  table). 

It  is  also  necessary  to  observe  that  accessories  must  harmonize  with 


380  THE  PRACTICE  OF  PHOTOGRAPHY. 

the  main  figure  (see  Arrangement,  Contour,  and  Lines),  and  they 
must,  because  they  are  accessories,  be  secondary  in  importance  to  the 
main  figure — L  e.,  they  must  neither  in  shape  nor  in  color  become  too 
prominent. 

High-lights  on  furniture  are  horrible,  but  much  more  so  are  zig- 
zag lines  or  ornaments  which  interfere  with  the  harmony  of  the  out- 
line.   A  glaring  design  in  the  carpet  or  curtain  is  unbearable. 

When  these  simple  things  offer  already  so  much  difficulty,  how  much 
more  complicated  must  it  be  when  the  whole  background  is  filled  up 
with  obtrusive  painted  landscape  scenery  or  architectural  objects. 
We  can  operate  with  real  objects ;  we  can  place  the  figure  in  an 
arbor,  in  a  window,  or  have  a  really  papered  wall,  where  everything 
which  is  necessary  to  the  picture  has  been  suitably  selected  and 
placed  in  the  proper  position.  Or  we  have  recourse  to  a  painted 
background.  There  are  many  of  them,  which  can  be  purchased  from 
the  stockdealer,  but  most  of  them  are  good  for  nothing. 

One  of  the  most  striking  shortcomings  of  the  painted  background 
is  the  accumulation  of  different  objects  and  the  diversity  of  the 
things  so  introduced ;  the  number  of  the  objects,  which  by  their 
smallness  are  to  indicate  the  distance,  while  the  sharpness  and 
solidity  with  which  they  are  painted,  places  them  immediately  back 
of  the  sitter,  and  the  perspective  becomes  at  once  wrong  when  the 
camera  is  not  placed  at  the  eye-point  of  the  picture. 

It  is  perfectly  clear  that  if  natural  objects  are  at  all  represented  in 
the  background,  it  should  be  done  under  the  same  conditions  as  the 
principal  figure  itself,  and  that  the  landscape  should  not  have  a  dif- 
ferent eye-point  from  the  model. 

The  horizon,  if  it  is  represented  at  all,  should  be  opposite  to  the 
lens.  For  a  time  it  was  the  fashion  amongst  portrait  painters  to  paint 
the  horizon  as  low  as  possible.  Of  course  the  figure  reached  to  the 
clouds,  and  appeared  very  gigantic ;  still,  such  a  picture  looks  very 
untrue. 

I  will  give,  as  an  instance,  the  one  picture  of  King  Frederick 
William,  in  Berlin.  He  stands  on  the  sandy  plain,  and  in  the  dis- 
tance is  "  Charlottenhof,"  reaching  as  high  as  the  knees  of  the  figure. 
Such  a  view  could  only  be  natural  when  the  painter  places  his  head 
on  the  ground,  or  when  the  figure  stands  on  an  eminence  and  the  ob- 
server below.  Reutlinger  has  made  some  good  pictures  where  the 
figures  reach  to  the  clouds ;  so  also  has  Robinson.  The  undefined 
cloud  forms  relieve  the  figure,  and  it  is  easy  to  place  the  light  face 
against  a  dark  cloud,  or  the  dark  hair  against  the  light  sky.  But  the 
horizon  should  not  extend  lower  than  the  hips. 


ACCESSORIES  AND  BACKGROUNDS. 


381 


A  faithfully  drawn  landscape,  but  without  much  detail,  and  which 
contains  nothing  which  will  draw  attention  to  lineal  perspective,  in 
which,  hence,  horizontal  lines  are  as  much  as  possible  avoided,  will 
always  be  effective,  and  need  not  contain  any  gross  errors,  even  if  it 
is  not  absolutely  true.  Some  backgrounds  of  Graf  and  Reutlinger 
show  this  in  a  remarkable  manner. 

Regarding  the  illumination  of  backgrounds,  it  may  be  difficult  to 
get  a  perfect  harmony  between  the  illumination  of  the  sitter  and  the 
objects  forming  the  background.  It  is  also  necessary  to  change  the 
illumination  with  the  different  models.  Some  require  more  top-light, 
others  more  side-light,  while  the  illumination  of  the  background  re- 
mains unchanged. 

This  causes  difficulties ;  but  when  the  backgrounds  are  originally 
painted  in  a  manner  to  correspond  with  the  general  illumination  of 
the  room,  and  when  light  and  shade  have  not  been  placed  in  too  vio- 
lent a  contrast,  it  becomes  easy  to  avoid  any  striking  errors.  In 
landscape  backgrounds  top-light  should  predominate  as  corresponding 
with  an  open  air  effect,  while  for  an  indoor  representation  a  side-light 
effect  would  correspond  better  with  the  light  entering  a  room  through 
the  windows.  It  would  of  course  be  very  bad  taste  if  the  sitter  re- 
ceived the  light  from  the  right  side,  while  on  the  background  the 
light  is  painted  as  coming  from  the  left. 

I  sometimes  meet  with  queer  combinations  on  the  background. 
Papered  rooms  only  separated  by  a  balustrade  from  a  rocky  coast  or  a 
desert  heath ;  ladies  in  a  ball-room  toilet  amongst  rocks  and  under  a 
threatening,  stormy  sky, — follies  which  spring  from  thoughtlessness, 
and  to  which  I  need  only  give  a  passing  condemnation.  I  must  also 
condemn  a  combination  of  different  styles  of  furniture,  as  Gothic,  Re- 
naissance, or  rococo.    Attention  should  be  paid  to  style. 

A  real  plastic  decoration,  as  a  pillar,  a  clock,  a  moulding,  or  a 
picture,  will  always  be  more  effective,  when  the  color  has  been  prop- 
erly selected,  than  a  painted  representation  of  the  same  object  in 
which  we  always  notice  the  pasteboard,  not  to  speak  of  the  incorrect 
perspective. 

Loescher  &  Petsch  have  for  this  reason  introduced  real  objects  in 
the  background  in  place  of  painted  ones. 

In  the  large  cities  it  is  easy  to  procure  good  backgrounds ;  but  in 
the  smaller  towns  the  matter  becomes  more  difficult.  The  photogra- 
pher orders  according  to  a  sample.  The  sample  looked  very  pretty 
and  full  of  effect,  but  in  using  it  everything  turns  out  entirely  differ- 
ent. What  is  to  be  done  now  ?  To  alter  it  is  difficult,  hence  it  re- 
mains as  it  is,  and  awful  things  come  to  light.    Still  the  fault  is  with 


382 


THE  PRACTICE  OF  PHOTOGRAPHY. 


the  photographer.  The  sample  was  taken  under  entirely  different 
circumstances. 

When  some  parts  work  too  glaring,  Mr.  Grasshoff  recommends  the 
following  background  retouch  :  Some  powdered  yellowish-brown  color, 
as,  for  instance,  gold,  or  Roman  ochre,  or  umber,  should  be  placed  in 
a  piece  of  linen  in  the  shape  of  a  pad.  With  such  a  contrivance  the 
light  places  are  rubbed  over,  and  the  yellowish  tone  will  produce  a 
more  subdued  effect.  In  a  similar  manner  spots  that  are  too  dark 
should  be  retouched  with  pulverized  chalk.  This  will  often  be  suffi- 
cient to  harmonize  effects,  which  are  otherwise  disturbing. 

That  the  background  appears  lighter,  if  the  person  stands  nearer, 
and  darker,  if  he  moves  further  away,  we  have  already  mentioned; 
that  the  background  appears  lighter  if  turned  towards  the  open  glass 
wall,  is  likewise  a  foregone  conclusion.  This  can  be  seen  with  the 
naked  eyes.  In  regard  to  the  contrast  between  the  lightness  of 
the  figure  and  the  background,  we  have  already  mentioned  the 
main  principle.  The  object  must  always  stand  off  perceptibly  from 
the  background.  The  background  should,  therefore,  be  darker  for 
light  hair,  and  vice  versa.  The  color  of  the  dress  must  also  be  con- 
sidered. 

The  following  rules  should  always  be  observed  :  Everything  which 
is  put  in  the  picture,  such  as  table-covers,  curtains,  and  furniture, 
must  be  subordinate,  and  must  not  show  more  prominently  than  the 
person,  and  the  lines  and  outlines  of  the  portrait,  the  costume  and 
everything,  must  form  a  harmonious  whole  with  the  above-named  ob- 
jects. 

The  less  we  stand  in  need  of  such  accessories  the  better  will  it  be. 
The  painted  background  will  never  be  more  than  a  make-shift.  It  is 
a  fault  when  the  background  occupies  three-quarters  of  the  picture,  as 
we  see  it  frequently.  The  size  of  the  figure  should  bear  a  certain  pro- 
portion to  the  whole  picture. 

It  is  astonishing  how  little  space  is  necessary  around  the  figure 
without  the  frame  appearing  too  narrow.  Take  Raphael's  Madonna 
Sedia,  which  contains  three  figures  in  the  narrowest  round  frame,  and 
still  it  does  not  make  an  unpleasant  impression. 

The  effect  of  a  figure  with  too  large  a  blank  space  about  it  is  easily 
seen  in  the  medallion  pictures,  which  are  frequently  taken  with  the 
carte  de  visite  apparatus  at  long  distances.  On  the  large  white  paper 
the  head  appears  much  smaller  than  if  we  cut  it  out  and  look  at  it 
separately. 

It  is  also  well  known  that  a  standing  figure  appears  more  slender 
when  the  head  touches  the  upper  margin  of  the  paper,  and  to  the 


ACCESSORIES  AND  BACKGROUNDS. 


383 


right  and  left  much  open  space  is  left ;  so  also  does  the  figure  appear 
stouter  when  much  upper  space  and  no  side  margin  is  left. 

Of  how  much  importance  accessories  are,  the  following  communi- 
cation of  Mr.  Priimm  will  explain  :  * 

A  little  lady,  only  four  feet  high,  complained  to  this  gentleman 
that  in  all  her  pictures  she  looked  so  very  diminutive.  Mr.  Priimm 
knew  how  to  obviate  this ;  he  placed  the  lady  next  to  a  toy  table  in 
front  of  a  plain  background,  and  took  a  three-quarter  length  picture. 
Alongside  the  little  table  the  lady  appeared  very  large,  and  she  was 
highly  pleased  with  the  effect.  Such  contrasts  have  in  many  instances 
extraordinary  effect. 

The  same  which  we  have  said  before  in  regard  to  disorder  in  the 
background  refers  with  increased  force  to  the  foreground.  It  is  wrong 
to  place  a  carpet  with  a  striking  design  or  glaring  colors  in  the  fore- 
ground. Such  designs  are  positively  ugly  when  their  figures  do  not 
correspond  with  those  of  the  picture. 

A  carpet  with  dull  colors  and  a  "quiet"  design  is  the  best  for  full- 
length  pictures.  Very  often  the  lustreless,  simple  floor,  or  a  grass 
carpet — the  latter  of  course  with  landscape  background — is  the  best. 

Finally,  there  should  be  harmony  between  floor  and  background 
in  shape  and  color.  A  background  which  is  placed  an  inch  above 
the  floor,  and  separated  from  the  latter  by  a  black  line,  will  always 
make  a  "  stagy  "  effect.  It  is  also  self-evident  that  a  figure  cannot 
throw  its  shadow  upon  a  landscape  which  is  considered  to  be  miles 
away.  A  certain  distance  between  the  person  and  the  background  is 
necessary. 

But  now  to  the  conclusion, — for  the  one  anxious  to  learn  and  to 
improve,  it  may  come  too  soon ;  for  the  impatient,  too  late. 

I  can  only  give  outlines.  The  realm  of  art  is  as  infinite  as  the 
realm  of  science,  and  many  a  one  will  exclaim  :  Too  much,  too  much! 
how  can  we  practical  photographers  pay  attention  to  all  these  trifles  ? 
Arrangement,  Outlines,  Drapery,  Background,  Accessories,  Perspective, 
Position,  Illumination,  etc.,  etc.  f  It  is  of  course  too  much  for  the  lazy 
one  and  for  the  thoughtless  one,  but  not  for  the  one  who  strives  to 
excel. 

In  the  world  of  art  the  greatest  masters  have  gained  the  highest 
success  by  restless  study  and  indefatigable  labor.  Look  at  the  studies 
of  Raphael ;  they  are  the  mute  and  yet  eloquent  witnessess  of  the 
colossal  preparations  which  this  greatest  painter  of  all  times  made  be- 
fore he  attempted  such  creations  as  the  "  Disputa,"  "  The  School  of 
Athens,"  "  The  Sibylla,"  and  other  masterpieces.  And  it  is  fortu- 
nate that  photography  is  not  only  a  mechanical  trade,  but  a  profession 


384 


THE  PRACTICE  OF  PHOTOGRAPHY. 


in  which  the  intelligent  and  ambitious  artist  will  always  outdistance 
the  merely  mechanical  worker. 

I  hope,  then,  this  book  of  mine  may  encourage  the  student  to  work 
on,  and  let  him  remember  the*  words  of  Socrates : 

«  The  beautiful  is  difficult." 


SUPPLEMENT. 

For  the  convenient  calculation  of  the  gramme  weights,  used  re- 
peatedly in  this  book,  into  ounces,  we  append  the  following : 

WEIGHTS  IN  PHOTOGRAPHY. 

Two  systems  of  weights  are  in  use  : 

1  ounce  =  8  drachms  =  24  scruples  =  480  grains. 
1  kilogramme  =  2  pounds  =  1000  grammes. 
1  gramme  =  10  decigrammes  =  100  centigrammes  =  1000  milligrammes. 
1  drop  (English  minim)  is  about  equal  to  1  grain  =  6  centigrammes. 


English  and  American  formula?  are  generally  given  in  ounces  and 
grains.  The  following  table  facilitates  the  conversion  of  the  one  sys- 
tem into  the  other: 


English  Weight. 

Grain  1 
"  2 
"  3 


Decimal  or  French  Weight. 

=  6.25  centigrammes. 
=  12.5  " 
=  18.75 


French  Weight. 


English  Weight. 


1  gramme 

16  grains. 

11 

grammes  =  176 

2  " 

32 

a 

12 

=  192 

3 

48 

(< 

13 

=  208 

4  " 

64 

(< 

14 

«       =  224 

5  " 

80 

II 

15 

"       =  240 

6  " 

96 

it 

16 

«  =256 

7  " 

112 

a 

17 

=  272 

8 

128 

ti 

18 

"       =  288 

9  " 

144 

u 

19 

"       =  304 

10  " 

160 

20 

«       ==  820 

=  4drs. 


1  cubic  centimetre  of  water  =  1  gramme  =  16  grains. 
32  cubic  centimetres  of  water  =  about  a  fluid  ounce. 


INDEX. 


A. 

Aberration,  spherical,  57 
Accessories  and  backgrounds,  374 
Acetate  of  soda  toning  bath,  175 
Achromatic  objective,  67 
Actinic  power  of  a  lens,  62 
Esthetics,  292 
Albumen  dry  process,  209 
Alkaline  toning  bath,  173 
American  Optical  Company  camera  boxes, 
47,  50 

Ammonia,  fuming  paper  with,  179 
Angle  of  view  of  a  lens,  62 
Apparatus,  care  of  the,  132 

and  the  chemicals,  care  of  the, 
132 

panoramic,  85 
Application  of  photography,  practical,  249 
Architecture  and  interiors,  278 
Arrangement  in  landscapes  and  architec- 
ture, 357 
of  human  figures,  353 
of  the  gallery,  17 
of  the  picture,  330 
Art  of  photography,  the,  292 

works  of,  how  to  photograph,  260 
Astronomical  photography,  284 
Atelier  of  the  Academy  Royal  of  Berlin,  18 
advantage  of  low  ones  for  single 

portraits,  36 
American,  30 

construction  of,  for  single  portraits, 

36,  38 
high,  37 
Reutlinger's,  36 
Salomon's,  36 
size  of,  27 
tunnel,  38 


B. 

Backgrounds,  accessories  and,  374 
arrangement  of,  41 
Balance  of  lines,  332,  376 
Bath,  Black's  acid,  107 

india-rubber,  120 

nitrate  of  silver,  106 

glass,  120 

porcelain,  120 


Bath,  the  positive  silver,  168 
the  toning,  170 
alkaline  gold  toning,  173 
care  of  the,  positive,  195 
chloride  of  lime,  173 
neutral,  gold,  175 

with  chalk  (after  Da- 

vanne),  175 
with    bicarbonate  of 
soda,  175 
borax  and  phosphate  of  soda,  173 
acid  toning,  1  75 
acetate  of  soda,  175 
Rhodan  gold,  176 
the  fixing,  176 
Bedford,  landscape  effects,  326 
Bendemann's  Jeremiah,  366 
Bendemann,  pyramidal   arrangement  of 

groups,  336 
Bicarbonate  of  soda,  for  toning  bath,  175 
Bichromate  of  potash,  for  carbon  process, 
238 

for  Vogel's  photo- 
meter,  245 
Bigelow  backgrounds,  379 
Black's  acid  bath,  107 
Brewster,  stereoscope,  84 
Brightness,  direct  in  the  atelier,  34 
Bromide,  ammonium,  196 

eadmium,  97 

lithium,  97 

potassium,  95 

sodium,  96 

zinc,  97 
Bromo-collodion  process,  213 
Busch.  E.,  comparison  of  lenses,  70 


C. 

Camera,  the,  45 

American,  50 
care  of  the,  133 
stand,  45 
stereoscopic,  264 
tube,  use  and  construction  of  the, 
51 

Carbon  paper,  238 

printing  bath,  238 
printing  process,  237 

25 


386 


INDEX. 


Carbon  prints  on  albumen  paper,  241 
Care  of  the  apparatus,  132 

camera,  133 

chemicals.  132 

collodion,  136 

developer,  142 

fixing  bath,  142 

intensifier,  142 

lenses.  133 

finished  negative,  143,  191 
negative  bath,  138 
glass  plates,  134 
varnish,  142 

utensils  and  chemicals  in  the 

positive  process,  191 
paper,  192 

positive  silver  bath,  195 
sensitized  paper,  200 
toning  bath,  201 
fixing  bath,  201 
Characteristics  and  individuality,  360 
Chemicals,  care  of  the,  132 

preparation  of  the,  88 
Children,  how  to  photograph,  373 
Chloride  of  lime  toning  bath,  173 
Chromatic   aberration    or   dispersion  of 

color,  58 
Collodion  bottles,  119 

care  of  the,  136 
cometless  bottle,  119 
equivalent,  Dr.  Vogel's,  104 
filter,  105 

Kurtz,  Loescher  &  Petsch,  104 
paper,  188 
permanence  of,  91 
plain,  85 

preparation  of  salted,  90,  102 
Dr.  Vogel's  sodium,  103 
Collodionizing,  117 

Collodio-albumen  process,  England's,  209 
Color,  dispersion  of,  58 
Combination  printing,  181 
Consumption  of  silver  in  printing,  169 

gold  in  toning,  173 
Copying  stand,  44 
table,  251 

the  direct  process,  235 

indirect  process,  235 
Cracking  of  the  negative  film,  192 
Curtains,  arrangement  of,  19,  20,  30 

white  and  lace,  35 
Curve  of  the  surface  of  the  picture,  59 
Cyanide  of  potassium,  110 


D. 

Dallmeyer  portrait  lens,  69 

triplet  lens,  68 
Davanne,  neutral  toning  bath,  175 

on  toning,  171 
Depth  of  focus  of  .a  lens,  62 
Developer,  the,  107 

care  of  the,  142 
Development,  the,  125 
Different  photographic  processes,  206 
Dipper,  120 


Disappearance,  point  of,  328 

Dishes  for  sensitizing,  121 

Disordered  bath,  how  to  treat  a,  139 

Dispersion  of  color,  58 

Distance,  effect  of,  on  pictures,  318 

Distortion,  60,  321 

Drawing  board,  44 

Drawings,  how  to  reproduce,  250 

Dresses  and  draperies.  346 

Dry  plates,  206 

process,  albumen,  209 
Dust  or  powder  process,  228 


E. 

Elevation  of  apparatus,  327 
Enamel  pictures,  with  gelatin,  189 

with  development,  236 
England's  collodio-albumen  process,  209 
Enlargements,  234 

the   indirect  printing  pro- 
cess, 235 
the  direct  copying  process, 
235 

Exclusion  of  extraneous  light,  124 
Excursions,  photographic,  articles  for,  274 
Exposure,  the,  124 

time  of,  124 


F. 

Failures  due  to  the  model,  144 

cleaning  and  polishing  the 

plate,  144 
the  collodion,  145 

silver  bath,  146 
exposure,  147 
development,  147 
in  intensifying,  148 

fixing,  148 
which  manifests  itself  on  drying 

the  plate,  148 
in  varnishing,  149 

the  negative  process,  143 
positive  process,  201 
silvering,  201 
printing,  202 
washing,  202 
toning,  202 
fixing,  203 

washing  after  fixing,  203 

finishing.  203 
Faults  of  the  paper,  177 
Ferrotypes,  248 
Field  of  view,  64 
Filling  the  picture,  374 
Finishing  the  print,  187 

failures  in,  203 
Fixing,  110 

the,  128 

bath,  care  of,  142 

positive,  176 

care  of  the  positive,  201 
failures  in,  203 
the  prints.  184 


INDEX. 


387 


Floating,  time  necessary  for,  178 

Focal  length  of  lenses,  table  of  differences 

in,  71 
Fog,  veils  or,  143 
Front-light,  303 

Fuming  of  paper  with  ammonia,  179 
Furnishing  of  the  gallery,  the,  40 


G. 

Gaffield,  on  glass,  Mr.,  30 

Gallery,  the  glass  house  and  accessory 

rooms,  form  of  the,  28 
Gelatinizing  of  photographs,  189 
Ghost,  cause  of,  63 
Girard  on  toning,  17 1 
Glass-house,  description  of,  28 

glass  for  it,  30 
Glass  plates,  how  to  clean,  111,  114 

care  of,  134 
Globe  lens,  76 

Gold,  consumption  of,  in  toning,  172 

solution,  normal,  172 
Grasshoff,  backgrounds,  376,  382 
Grune's  method  of  transferring  on  wood, 
233 

Gun-cotton,  90 

H. 

Half-tone,  or  mezzotints,  182 
Hance's  ground-glass  substitute,  31 
Hands,  arrangement  of  the,  355 
Hardwich  collodion,  96 
Harnecker  dry  plates,  211 
Harrison  &  Schnitzer,  Globe  lens,  76 
Head-rest,  Scovill  Manufacturing  Co. 's,  43 
Tuscan,  43 

Wilson's  Improved,  43 
Hearn's  Practical  Printer,  183 
Holmes  stereoscope,  85 
Hyposulphite  of  soda,  110 


I. 

Illumination  and  light,  300 

effect  on  character,  303 
effect  on  color,  305 

Image,  size  of,  56 

Imperfect  negatives,  how  to  print,  181 
Individuality,  characteristics  and,  360 
Instantaneous  pictures,  269 
Intensification,  the,  127 

after  fixing,  129 
Intensifier,  the,  108 

care  of,  142 
Intensity  of  light  at  different  seasons  of 

the  year,  124 
Interiors,  278 
Iodide  of  ammonium,  96 

cadmium,  97 

calcium,  97 

lithium,  97 

potassium,  95 


Iodide  of  silver  in  the  bath,  how  to  re- 
move, 141 
sodium,  96 
starch,  186 
zinc,  97 
Iodizing  salts,  94 

action  of  the,  98 
permanence,  98 
photographic  qualities,  99 
solubility,  99 
Ivory,  printing  on,  241 


J. 

Jacobsen,  Dr.,  on  the  use  of  permanganate 

of  potash,  139 
Jagemann,  C.  V.,  portraits,  36,  335,  343 


K. 

Kilburn's  varnish,  111 
Kits  for  plate-holders,  49 
Kurtz  on  backgrounds,  378 
collodion,  104 


L. 

Landscapes  and  architecture,  357 
lenses,  67 

Lea's,  M.  Carey,  bromo-collodion  process, 
213 

Lenses,  care  of  the,  133 
the  Globe,  76 

Orthoscopic,  73 
Triplet,  74 

Steinheil  aplanatic,  75 
Ross,  52,  70 
simple  forms  of  the,  54 
Leonardo  da  Vinci,  "Last  Supper,"  337 
"  Lichtpaus  "  process,  the,  258 
Light  in  the  studio,  principles  of  distribu- 
tion of,  31 
amount  of,  in  lens,  62 
and  illumination,  300 
Lighting,  effects  of  various  methods  of,  303, 
304 

Lines  and  outlines,  342 

Loescher  &  Petsch,  backgrounds,  377,  381 
system    of  arranging 

curtains,  19 
collodion,  104 
plan  of  gallery,  23 


M. 

Madonna,  after  Van  Eyck,  347 

Fra  Bartolommeo,  348 
by  Raphael,  344 
Machinery,  how  to  photograph,  260 
Masks,  for  prints,  how  to  use,  181 
Meagher's,  travelling  camera,  276 
Medallions,  on  a  gray  or  black  ground,  182 
Milster's  atelier,  28 


388 


INDEX. 


Metzu,  arrangement  of  groups,  345 
Mezzotints,  182 
Microphotography,  278 
Mieris,  arrangement  of  groups,  339 
Models,  photographing  of,  260 
Mohr,  burettes,  198 


N. 

Negative  process,  88,  131 

preparations,  131 
operations,  131 
care  of  the,  191 
how  to  reproduce,  228 
imperfect  ones,  how  to  print,  181 
reversed,  241 
Nitrate  of  silver  bath,  the,  106 


0. 

Obernetter's  dust  process,  228 
Objective,  the  portrait,  68 

construction  of,  54 

Dallmeyer  portrait,  69 

rectilinear,  79 
triplet,  68,  74 

Globe  lens,  76 

how  to  test,  79 

qualities  of,  66 

Petzval,  69 

Ross  landscape,  52 

Steinheil  aplanatic,  45 

Voigtlander,  69 

Zenlmayer,  78 
Objectives,  description  of  photographic,  66 
Oil  paintings,  how  to  copy,  250 
Operations  in  the  silver  positive  process, 
206 

photographic,  113 
Ornaments,  how  to  copy,  260 
Orthoscope  lenses,  73 

Ost,  bath  for  permanent  positive  papers,  200 
Oval  pictures,  182 
Over-exposure,  how  to  detect,  126 


P. 

Panoramic  apparatus,  85 
Pantoscope,  the,  76 
Paper,  care  of  the,  194 
faults  of  the,  177 
permanent,  for  printing,  200 
sensitizing  the,  178 
Paton's  profile  sketch,  335 
Perfect  camera  stand,  Am.  Opt.  Co.'s,  45 
Permanent  sensitive  negative  plates  (dry 
plates),  206  . 
positive  paper,  200 
Permanganate   of  potash  for  disordered 

bath,  139 
Perspective,  313 

and  distance,  321 
Petzval  portrait  lens,  62,  69 
Phosphate  of  soda  in  toning,  173 


Photographic  excursions,  270 

objectives  (tubes)  and  lenses, 

54,  66 
operations,  the,  \IS 
Photographing  of  models,  ornaments,  stat- 
ues, works  of  art,  machinery,  etc.,  260 
Photography  and  truth,  293 
art  of,  292 

practical  application  of,  249 
Photometer,  Dr.  Vogel's,  242 
Pictures,  how  to  transfer,  232 

instantaneous,  269 
Pigment  prints  on  albumen  paper,  241 
Plates,  care  of  the,  134 
cleaning  the,  1 14 
preliminary  coating  for,  116 
dusting  the,  117 
collodionizing  the,  117 
sensitizing  the,  119 
Plate-holder,  48 

corners  of  the,  49 
Position  and  standpoint,  353 
Positive  or  silver  printing  process,  162 
process,  failures  in  the,  201 
silver  bath,  care  of  the,  195 
Positives  on  glass,  221 
Press  for  finishing  prints,  188,  189 
Printing,  the,  180 
room,  31 

by  development,  236 
carbon  process,  237 
combination,  181 
frames,  164 

from  imperfect  negatives,  181 
failures  in,  202 

the  positive  or  silver  process,  162 
the  paper,  165 

positive  bath,  168 
practice  of  the  silver  pro- 
cess, 177 
solar  camera,  236 
vignettes,  180 
with  several  negatives,  181 
Prints,  finishing  operation,  187 
Public,  treatment  of,  370 
Pyramidal  arrangement,  336 
Pyrogallic  acid  for  intensifying,  115 
Pyroxylin,  90 


R. 

Rabending,  atelier  of,  18,  22 
Reduction  of  silver  residues,  203 
Reflecting  screen,  312 
Relief  printing  process,  315 
Rembrandt  effects,  310 
Reproduction  of  negatives,  221 ,  228 

photographic,  250 
Reproductions,  preparation  of  the  original, 
250 

arrangement,  250 
illumination,  252 
the  lenses,  252 
protection  of  the  objective 
against  foreign  light,  252 
time  of  exposure,  254 


IND*EX. 


389 


Reproductions,  methods  of  operation — for- 
mulae, 255 
the  printing,  256 
criticism  of  the  result,  257 
Resin  dry  plate  process,  211 
Retouch,  aesthetical  principles  of  the  nega- 
tive, 156 
Retouching,  negative,  149 
varnish,  151 
Reutlinger,  atelier  of,  36 
Reversed  negatives,  241 
Rhodan  gold  toning  bath.  141 
Rietschel's  statue  of  Lessing,  331 
Luther,  362 
Robinson,  landscape  composition,  341 
Ross  lenses,  52,  70 
Russell's  tannin  process,  213 


S. 

Salomon,  Adam,  accessories,  282 
atelier  of,  30 
background,  378 
portraits,  36 
Scamoni's  method  of  copying  imperfect 

pictures,  250 
Schaarwachter's  arrangement  of  curtains, 
27 

Scovill  Manufacturing  Co.'s  cameras,  265 
Secondary  picture,  cause  of,  63 
Sensitized  paper,  care  of,  200 

permanence  of,  200 
Sensitizing,  the,  119 

in  the  bath,  120 

in  dishes,  121 

the  paper,  178 
Side-light,  303 
Silver  bath,  care  of  the,  138 

printing  process,  162,  177 

consumption  of,  in  printing, 
169 

residues,  how  to  reduce,  203 

tester,  198 
Spectral  photography,  282 
Spherical  aberration,  58 
Standpoint,  position  and,  353 
Statues,  how  to  photograph,  260 
Steinheil's  apian  a  tic  lens,  75 
Stereoscope,  the,  83 
Stereoscopic  camera,  264 

pictures,  264 
Stops  for  objectives,  51 
Succession  of  different  photographic  oper- 
ations in  negative  and  positive  process, 
131 

Summary  and  successive  operations  in  the 

silver  positive  process,  206 
Supplement,  384 
Sutton,  collodion,  86 

T. 

Tannin  process,  213 
Technical  errors,  319 
Tent  work,  270 

Terburg,  arrangement  of  groups,  273 


Tester,  silver,  198 

Thorwaldsen's,  bas-reliefs,  338 

statue  of  Byron,  351 
triumphal  march  of  Alexan- 
der, 365 

Toning  bath,  the,  170 

acetate  of  soda,  175 
alkaline,  gold,  173 
acid,  175 

bicarbonate  of  soda,  175 
borax    and   phosphate  of 

soda,  173 
care  of  the,  201 
chloride  of  lime,  173 
neutral,  gold,  175 
rhodan  gold,  1 76 
with  chalk  (after  Davanne), 

175 

Toning,  the,  183 

failures  in,  202 
Top-light,  303 

Transferring  of  photographs  to  other  sur- 
faces, 232 
with  ordinary  collodion,  232 
Transparent  positives,  production  of,  221 

by  printing,  224 
Treatment  of  the  public,  370 
Truth  and  photography,  293 
Tunnel  atelier,  38 

U. 

Under-exposure,  how  to  detect,  126 


V. 

Varnish,  the,  110 

care  of  the,  142 
Varnishing,  the,  129 
Ventilation,  31 
Vogel's,  Dr.,  collodion,  104 

photometer,  242 

test  for  silver  bath,  198 
Voigtlander,  69 

carte  de  visite  lens.  70 

lens,  70 

W. 

Washing  after  fixing,  the,  184 

failures  in,  203 
failures  in,  202 
apparatus,  185 

prints,  test  for,  sufficient,  186 
Watering,  the,  183 
Weights  in  photography,  384 
Wheatstone  stereoscope,  84 
Works  of  art,  how  to  photograph,  260 

X. 

Xylographs,  233 

Z. 

Zentmayer  lens,  78 


SCOVILL 

MANUFACTURING  COMPA 

NY, 

DEALERS  IN 

Everything  Pertaining 

II 

TO 

PHOTOGRAPHY 

1 

I 

AND 

Pro p  wie  t  O  FM 

1 

Aimmiemm.  Optical  § 

419  &  421  BROOME  ST., 

591 

ROBINSON'S 

PHOTOGRAPH  TRIMMER 

IS  A  SUBSTITUTE  FOR  A  KNIFE 

For  trimming  photographs  and  does  the  work  much  more  expeditiously 
and  elegantly  than  a  knife. 

It  Saves  Time,  Saves  Prints,  and  Saves  Money. 

The  accompanying  cut  represents  the  instrument  in  the  act  of  trimming 
a  photograph.  It  does  not  cut,  but  pinches  off  the  waste  paper,  and  leaves 
the  print  with  a  neatly  bevelled  edge  which  facilitates  the  adherence  of  the 
print  to  the  mount.  Try  one,  and  you  will  discard  the  knife  and  punch 
at  once.    For  ovals  and  rounded  corners  it  is  worth  its  weight  in  gold. 


Oil  the  wheel  bearings  with  Sewing 
Machine  Oil. 


ROBINSON'S  IMPROVED  GUIDES. 

The  difficulty  of  procuring  exactly  true  guides  for  cutting  out  prints  has 
induced  the  inventor  to  put  up  machinery  for  the  production  of  all  styles 
of  them,  guaranteed  mathematically  true. 

A  Full  Stock  of  Regular  Sizes  now  on  Hand. 

BENERMAN  &  WILSON,  Maiinf's  Apis, 

PHILADELPHIA,  PENNA. 

392 


Awarded  the  HOLMES  MEDAL  at  the  Chicago  N.P.A.  Exhibition,  1874. 


MoBLTors  Rapid  Photo-Wisher. 


Patented  August  12,  1873. 

New  in  Principle —  Quick  and  Reliable  in  Practice. 


Instead  of  soaking  the  Prints  it  applies  the  water  in  the  form  of  spray, 
with  considerable  force,  to  both  sides  of  the  paper  at  each  revolution,  or 
from  one  hundred  to  one  hundred  and  fifty  times  per  minute.  Washes 
with  exact  uniformity,  and  gives  more  brilliant  and  permanent  work  ;  is 
simple,  not  liable  to  get  out  of  order,  will  last  a  lifetime,  and  will  enable 
you  to  get  out  work  at  short  notice,  thereby  securing  many  orders  that 
would  otherwise  be  lost. 

Capacity  in 

Size  Cylinder.  Cards.  Largest  Print.  Price. 

Diam,  16  in,,  Length  14  1-2  in.       84       14  by  17  ins.  $30 
"20         "      19  144      18  by  22  40 

"     25         "      24  220      22  by  28  50 

Every  machine  has  given  entire  satisfaction,  as  far  as  heard  from.  The 
following  is  a  fair  sample  of  the  numerous  testimonials  received  : 

Mr.  Moulton.  Chicago,  October  19, 1874. 

Dear  Sir  :  The  Washer  is  splendid  !  Could  not  do  without  it.  It 
washes  the  prints  better  in  fifteen  minutes  than  by  the  old  tank  process  in 
all  night.    Wishing  you  every  success,  we  remain, 

Very  truly,  E.  L.  Brand  &  Co. 

L.  V.  MOULTON,  Beaver  Dam,  Wis. 

393 


tih:  is 


ZENTMAYER  LENS, 

FOR  VIEWS  AND  COPYING. 


Although  only  the  short  period  of  six  years  has  elapsed  since 
this  lens  was  first  introduced,  it  has  already  become  widely  popular, 
and  its  excellent  qualifications  well  established,  which  are  pre- 
eminently as  follows:  i 

Width  of  Visual  Angle,  Ranging  from  80°  to  90°  ; 
Depth  of  Focus  ; 

Extreme  Sharpness  over  the  Whole  Field; 
True  Perspective  ; 

Freedom  from  all  Distortion  in  Copying  ; 
Portability  and  Cheapness. 

Each  mounting  is  provided  with  a  revolving  diaphragm,  con- 
taining the  stops  of  the  different  combinations  for  which  they  are 
designed.  The  larger  ones  are  provided  with  an  internal  shutter 
for  making  and  closing  the  exposure. 


No.  1—2%  in.  focus,  3x3  plate 
"  2—3%       "       4x5  " 
"  3-5%       "    6%x8%  " 
"  4—8  "      10x12  " 

"  5—12  "  14x17  " 
"  6—18         "      20x24  '•' 


$20  00 
25  00 
30  00 
42  00 
60  00 
90  00 


Nos. 


1  and  2  combined, 

2  "  3 

3  "  4 

4  "  5 

5  "  6 
1,  2,  and  3 

Nos.  3,  4,  and  5  combined,  $88.00. 


$33  00 
40  00 
55  00 
75  00 

110  00 
48  00 


No.  3,  with  large  mounting  to  combine  with  Nos.  4  and  5,  $35. 

Nos.  1  and  2,  specially  adapted  for  Stereoscopic  views,  are  fur- 
nished in  matched  pairs.  No.  1,  single,  not  to  combine  with  other 
sizes,  $36  a  pair.  This  size  is  constructed  for  special  cases  where 
the  largest  possible  angle  is  required. 

Lenses  and  mountings  to  form  all  six  combinations,  from  2\  to 
18  inches,  $173. 

For  further  particulars,  please  address 


394 


JOSEPH  ZENTMAYER, 

147  S.  Fourth  St.,  Philadelphi 


LAFAYETTE  W.  SEAVEY, 

ARTIST, 

AND  DEALER  IN 

Photographic  Backgrounds, 

PLAIN,  LANDSCAPE,  INTERIOR,  AND  REMBRANDT. 
Also,  Slips,  Rustic  Fehces,  Artificial  Rocks,  etc.,  etc. 

Theatrical  Scenery  for  Public  Halls,  Amateurs,  etc.,  to  let  and  for  sale. 
Designer  and  dealer  in  Patterns,  Pounces,  etc.,  for 
Fresco  and  Scenic  Artists. 


No.  8  LAFAYETTE   PLACE,  NEW  YORK. 


SEAVEY' S  ANTIQUE  CABINET.  — Papier  mache,  a  popular  and 
valuable  accessory  in  full  lengths  and  genre  pictures.  The  gen- 
uine article  in  oak  and  bronze  would  cost  $400.     Price   $40  00 

No.  32. — Sarony  Interior  and  Reutlinger  combined,  per  square  ft.,  30 

No.  66. — Mora  Cabinet,  a  popular  design,  per  square  ft  ,   30 

No.  67. — Cabinet  Background,  per  square  ft   30 

No.  68. — A  Standard  Interior,  three  backgrounds  combined,  ex- 
cellent for  general  use,  per  square  ft.,   30 

No.  69. — Sarony  Moonlight,  per  square  ft   25 

No.  70  — Mora  Interior,  for  full  and  three-quarter  lengths,  per 

square  ft. ,   30 

No.  72. — Rocher  Tapestry,  for  use  in  general  pictures,  and  with 

our  antique  cabinet  and  chair,  per  square  ft.,   30 

No.  20. — Fredricks'  Sea  View,  per  square  ft.,   25 

No.  21. — Mora  Sea  View,  adapted  for  head  and  vignette,  as  well  as 

full  lengths,  per  square  ft.,   25 

SEAVEY'S  REMBRANDT. — 5  x  5  square,   5  00 

FRAME,  AND  IRON-JOINTED  ATTACHMENT,    7  00 

SEAVEY'S  PAPIER  MACHE    ROCKS.— Large,  medium,  and 

small,  for  use  with  Landscape  and  Sea  View,  full  set,   25  00 

GARDEN  BALUSTRADE.— Mounted  on  castors,  trimmed  with 
artificial  vines,  etc.  A  popular  and  superior  photographic  ac- 
cessory.   Price,   35  00 

ANTIQUE  CHAIR. — Carved  oak  frame  papier  mache  back  ;  the 

back  detached  forming  a  stool.    Price,   15  00 

NEW  STYLE  PAPIER  MACHE  ROCK— Mounted  on  feet  and 
castors,  same  as  Background,  reversible,  upper  part  detaches, 

and  can  be  used  separately.    Price   20  00 

BACKGROUND  FEET.— Stained  and  mounted  on  castors.  Price, 

per  pair     2  50 

FINE  IMPERIAL  CARDS.— Showing  our  backgrounds  and  ac- 
cessories, and  manner  of  using,  from  the  principal  New  York 
galleries,  sent  by  mail,  each,   25 


ROLLERS,  BOXING,  AND  0 ART  AGE EXTRA. 

395 


IMPROVED 

Photograph  Covers 


Frequent  inquiries  for  something  at  a  much  lower  price  than  an  album, 
for  the  holding  together  and  preservation  of  photographs,  has  induced  us 
to  manufacture  an  article  which  we  think  will  meet  the  want. 

IT  SERVES  ALL  THE  PURPOSES  OF  AN  ALBUM,  FOR 

A  SERIES  OR  A  SET  OF  PORTRAITS,' 

A  SERIES  OR  A  SET  OP  LANDSCAPES, 

A  SERIES  OR  A  SET  OF  PHOTOGRAPHS, 
OF  ANY  KIND, 

May  be  neatly  and  cheaply  bound  in  these  covers. 


They  are  made  with  expanding  backs,  so  that  from  six  to  twenty-four 
pictures  may  be  inserted  in  one  cover.  The  pictures  are  mounted  in  the 
usual  way,  and  then  strips  of  linen  or  strong  paper,  of  the  proper  width, 
are  pasted  on  one  edge,  by  which  the  picture  is  inserted  and  held  in  place 
in  the  cover  by  a  paper  fastener.  Their  arrangement  is  simple,  and  we 
are  sure  will  be  readily  comprehended.  For  binding  together  views  of 
your  town  or  city,  or  portraits  of  celebrities,  they  are  very  neat. 

THE  FOLLOWING  IS  A  LIST  OP  SIZES  AND  PRICES,  WITHOUT  CARDS : 

For  Photograph.  Per  dozen.  Per  hundred. 

Card  size   $1  50    $10  00 

Cabinet  size   2  25    13  50 

EXTRA  HEAVY  COVERS. 

5-8  size   4  50    S3  00 

4-4    "    6  00    40  00 

8-10.  "    8  00    56  50 

11-14  <:    10  00    70  00 

Larger  or  special  sizes  made  to  order.  Furnished  with  card  board  at 
best  rates.    Samples  mailed  at  dozen  price. 

BENERMAN  &,  WILSON,  Photo.  Publishers, 

Seventh  and  Cherry  Sts.,  Philadelphia. 

396 


DO  YOU  USE 


Waymouth's  Vignette  Papers ! 

(Designs  Copyrighted.) 

Of  all  pictures  the  vignette  is  the  most  artistic,  when  properly  printed ; 
but  the  clumsy  devices  generally  in  use  for  printing  them,  or  rather  for 
blending  the  shading  about  the  figure,  produce  but  very  few  really  artistic 
vignette  pictures.  Either  the  shading  is  too  intensely  dark,  not  gradated 
in  tint  at  all,  or  it  shows  an  ugly,  direct,  decided  line,  which  is  very  repul- 
sive. The  shading  should  blend  gradually  from  the  dark  tint  nearest 
to  the  figure  off  into  the  white  background.  The  results  are  then  soft, 
artistic,  and  beautiful.  The  easiest  and  best  way  to  secure  them  is  by  the 
use  of 

WAYMOUTH'S  VIGNETTE  PAPERS. 

They  are  not  clnmsy  ;  do  not  break ;  are  always  ready ;  cost 
but  little ;  and  are  easy  of  application  to 
any  negative. 


They  entirely  do  away  with  all  the  old  and  troublesome 
methods,  either  wood,  metal,  or  cotton. 


They  need  but  one  adjustment  to  print  any  quantity. 


Eighteen  sizes  are  now  made,  suiting  all  dimensions  of  pictures,  from  a 
small  carte  figure  to  whole  size,  Victorias,  Cabinets,  etc.  They  are  printed 
in  black  for  ordinary  negatives,  yellow  bronze  for  thin  negatives,  and  red 
bronze  for  still  weaker  ones.    Directions  for  use  accompany  each  parcel. 

PRICES : 

In  parcels  containing  one  of  each  size,  Nos.  1  to  15,  assorted  colors,  $1  00 


Assorted  sizes  and  colors,  by  number,  per  package  of  fifteen   1  00 

ASSORTED  SIZKS  AND  COLORS,  PER  DOZEN. 

Nos.  1,2,  3, 4,  and  5,  for  Cartes,  by  number  ,  50 

Nos.  6,  7,  11,  12,  and  13,  Large  Cartes  and  Victorias,  by  number   75 

Nos.  8,  9,  10,  14,  and  15,  Cabinets  and  Whole  Size,  by  number   1  00 

Nos.  16,  17,  and  18,  Half  and  Whole  size,  by  number   1  25 


When  ordering,  state  the  number  and  color  you  want.  The  Waymouth 
Vignette  Papers  are  an  English  invention,  and  are  becoming  so  universally 
used  in  Europe  that  we  have  pleasure  in  introducing  them  to  our  patrons. 

BENEEMAN  &  WILSON,  Manufacturers, 

Seventh  and  Cherry  Sts.,  Philadelphia. 

4®-  FOR  SALE  BY  ALL  DEALERS. 

397 


ELECTROTYPES  OF  THIS  DESIGN,  MORTISED, 
Sent  to  any  address  on  receipt  of  $1.50. 


Views  of  Buildings,  Machinery,  Stoves,  Portraits,  Seals,  Auto- 
graphs, Maps,  Tinted  Envelopes,  Monograms,  Posters,  News- 
paper Headings,  Catalogue  and  Book  Illustrations. 

Particular  Attention  Paid  to  Engravings  of  Machinery, 

And  all  work  requiring  elaborate  details. 

Parties  living  at  a  distance  can  have  engrav- 
ings made  by  sending  a  photograph  of  the 
articles,  or  a  sketch  on  paper,  and  they  may 
rely  on  the  work  being  done  with  promptness, 
and  in  a  manner  to  give  satisfaction. 

N.B. — Liberal  commissions  to  photographers 

who  will  so- 
licit orders 
for  us. 


No.  8.— Sent,  postpaid,  on 
receipt  of  $1. 

For  Photographers  and  Others. 

We  have  on  hand  a  variety  of  elec- 
trotyped  designs  (similar  to  the  cuts 
on  this  page),  mortised  to  admit  of 
type  being  set  in,  for  Cards,  Circulars, 
<^Bill  and  Letter  Heads,  backs  of  Card 
l^^lSx Mounts.  Newspaper  Advertisements, 
etc.   Also,  different  sizes  of  N.  P.  A. 
oiMMiiwKVM  Monograms  and  the  Vienna  Prize 
No.  3.— Sent,  postpaid,  on  receipt  of  $2.50.  jyje(jais 

Send  for  Circular. 

398 


NEW!  PHOTO.  PUBLICATIONS  IV  RW 


Owing  to  the  late  fire  in  our  office  and  to  the  fact  that  sev- 
eral photographic  books  are  out  of  print,  we  are  obliged  to 
issue  a  revised  or 


NEW  CATALOGUE! 


TO  WHICH  WE  CALL  YOUR  ATTENTION. 

There  is  something  for  the  workers  in  all  branches  of  the  art — ope- 
rators, posers,  manipulators,  printers,  painters,  retouchers,  finishers, 
and  art  students — all  are  provided  for. 

We  always  find  the  photographer  who  reads  what  is  published 
pertaining  to  his  profession,  to  be  the  photographer  who  succeeds 
in  his  business  the  best.  Above  all,  those  who  regularly  and  con- 
tinually receive  a  good  photographic  magazine  are  those  who  are 
always  ahead  with  new  goods,  new  styles,  and  new  information. 
We  recommend  an  investment  in  a  part  or  all  of  the  list  below, 
and  will  be  glad  to  mail  them  to  you  on  receipt  of  price. 


CATALOGUE. 


The  Philadelphia  Photographer.  The  oldest,  best,  and  most  Popu- 
lar Photographic  Magazine  in  America.  Twelfth  Year.  Please  read  the  pros- 
pectus on  page  three  of  cover  and  premium  list  in  red  letters.  Subscription 
price,  %o  a  year,  $2.50  for  six  months,  in  advance.  Current  number,  50  cents. 
Specimen  copies,  free. 

Photographic  Mosaics.  The  1875  edition  is  just  out  and  is  capital.  The 
list  oi  articles  is  made  up  of  contributions,  especially  for  its  pages,  on  all  de- 
partments of  the  art,  wholly  by  practical  men.  144  pages.  Paper  cover,  50 
cents.   Cloth,  $1.   A  few  copies  of  former  editions,  from  1866,  at  same  price. 

Bigelow's  Album  of  Lighting-  and  Posing.  This  is  not  exactly  a 
book,  but  a  collection  of  24  large  Victoria  size  photographic  studies  in  light- 
ing and  posing,  made  especially  to  teach  how  to  light  and  pose  ordinary  and 
extraordinary  subjects  in  all  the  plain,  fancy,  "Kembrandt,"  and  "Shadow  " 
styles.  It  is  accompanied  by  an  explanatory  key  of  instructions,  together 
with  a  diagram  for  each  picture,  showing  how  the  sitter  and  the  camera  were 
placed  in  the  skylight,  their  relation  to  the  background,  and  what  blinds 
were  opened  and  closed  at  the  time  of  the  sitting.  It  almost  supplies  a  rule 
by  which  you  can  quickly  tell  how  to  manage  every  subject  that  comes  to 
you.  The  studies  are  mounted  on  folding  leaves,  so*  that  twelve  can  be  ex- 
amined at  once.   Price,  in  cloth,  gilt,  $6,  postpaid. 

How  to  Paint  Photographs  in  Water  Colors.  A  practical  Hand- 
book designed  especially  for  the  use  of  Students  and  Photographers,  contain- 
ing directions  for  brush  work  in  all  descriptions  of  Photo-Portraiture,  Oil, 
Water  Colors,  Ink,  How  to  Retouch  the  Negative,  &c.  By  George  B.  Ayres, 
Artist.   Third  edition.   Differing  largely  from  previous  editions.   Price,  $2. 

399 


Handbook  of  the  Practice  and  Art  of  Photography.  By  Dr. 

H.  Vogel.  Second  edition  now  ready,  $3.50.  Much  enlarged  and  improved. 
The  best  of  all  photo-handbooks. 

The  Practical  Printer.  Issued  July,  1874.  A  capital  working  manual, 
giving  the  fullest  information  on  all  styles  of  photographic  printing  on  al- 
bumen and  plain  paper,  and  on  porcelain.  By  C.  W.  Hearn.  No  book  was 
ever  more  needed.  $2.50. 

Lea's  Manual  of  Photography.  Third  thousand.  $3.75  per  copy.  A 
capital  book  of  instructions  in  all  branches  of  the  art. 

How  to  Sit  for  Your  Photograph.  This  is  a  fine  little  work  of  48 
pages,  written  by  the  wife  of  a  celebrated  New  York  photographer,  for  the 
purpose  of  educating  the  public  on  the  all-important  subject  of  sitting  for  a 
picture.   It  is  bound  in  cloth  at  60  cents  per  copy,  and  paper  cover  30  cents. 

Lookout  Landscape  Photography.  By  Prof.  E.  M.  Linn,  Lookout 
Mountain,  Tenn.  A  pocket  manual  for  the  outdoor  worker,  and  full  of  good 
for  every  photographer.   75  cents.   Be  sure  to  get  it. 

Himes's  Leaf  Prints;  or,  Glimpses  at  Photography.  By  Prof. 
Charles  F.  Himes,  Ph.D.  Full  of  useful  information  for  t lie  photographic 
printer.   Illustrated  with  a  whole-size  photograph.   Cloth,  $1.25. 

The  American  Carbon  Manual.  By  Enw.  L.  Wilson.  A  complete 
manual  of  the  Caibon  process  from  beginning  to  end.  With  a  fine  example 
by  the  process.   Cloth,  $2. 

The  Photographer  to  His  Patrons.  A  splendid  little  twelve-page 
leaflet,  which  answers  all  vexatious  questions  put  to  you  by  your  sitters,  and 
serves  as  a  grand  advertising  medium.  It  is  for  photographers  to  give  away 
to  their  customers.  Send  for  a  copy  and  an  illustrated  circular.  Over  300,000 
already  sold  and  in  use  all  over  the  country.  $20  for  1000,  $35  for  2000,  and 
so  on.   Printed  and  supplied  in  English,  German,  and  Spanish. 

Something  New.  Just  out.  Similar  to  "  The  Photographer  to  His  Patrons," 
but  newer.   Prices  the  same. 

Pretty  Faces.  A  leaflet  much  smaller  than  "The  Photographer  to  His 
Patrons,"  and  "Something  New,"  for  the  same  purpose  hut  costing  less,  viz.: 
1000  copies,  $10 ;  2000,  $17.50,  and  larger  orders  at  less  rates. 

Elbert  Anderson's  Photo-Comic  Allmyknack.  A  complete  Al- 
manac, full  of  witty  sayings,  jokes,  puns,  stories,  etc.,  etc.  Profusely  illus- 
trated with  comic  and  original  sketches,  yet  all  interspersed  with  much 
practical  matter  of  value  to  every  photographer.   Price,  75  cents. 

Photographers'  Pocket  Reference-Book.  By  Dr.  H.  Vogel,  of 
Berlin.  A  dictionary  of  all  the  terms  used  in  the  art,  and  contains  formulas 
for  almost  every  known  manipulation.  Altogether  different  from  any  work 
ever  published.   Cloth,  $1.50.   A  splendid,  indispensable  book. 

The  Ferrotyper's  Guide.  Sixth  thousand  just  issued.  The  best  work 
ever  published  on  the  lerrotype.   Price,  75  cents. 

Wilson's  Lantern  Journeys.  By  Edward  L.  Wilson,  Editor  Phila- 
delphia Photographer.  Tells  all  about  six  hundred  of  the  beautiful  places  of 
this  earth.   218  pages.   Cloth  and  gilt,  $2.   See  advertisements. 

Works  found  in  our  old  catalogues,  and  not  in  the  above,  are 
out  of  print  and  cannot  be  had. 

BENERMAN  &  WILSON, 

Photographic  Publishers,  Philadelphia. 


Benerman  and  Wilson's  Publications  sold  by  all  Dealers. 
400 


BALTIMORE! 


THE  ATTENTION  OF  PHOTOGRAPHERS  is  invited  to  my  stock  of 
photographic  goods.  I  am  prepared  to  fill  all  orders,  large  or  small, 
promptly  at  best  prices. 

Ait  Tttr  .1VOV£tTI£0 

Are  received  as  soon  as  by  any  one  in  the  market. 


AMONG  OTHER  THINGS, 

The  American  Optical  Co.'s  Apparatus, 
Entrekin's  Oscillating  Enameier, 
Chute's  Universal  Cameo  Press, 
Robinson's  Print-Trimmers  and  Guides, 
Morrison's  and  Steinheil's  View  Lenses, 
Waymouth's  Vignette  Papers, 

All  Makes  of  Portrait  Lenses, 

Chemicals,  Glass,  and  Frames, 

Are  carefully  selected  for  my  special  sales.  My  expenses  are  light.  I  do 
my  own  work  personally,  and  can  supply  goods  as  low  as  the  next  one. 

A  trial  order  solicited.  Freight  and  expressage  from  Baltimore  very 
low  to  any  point  South  or  West. 


CHAS.  A.  WILSON, 

IT    n  NORTH  CHARLES  ST.,  fjt 
111  0.  I      BALTIMORE,  MD.     11 0. 

401 


2(3 


J.  P.  BEARD  *  CO. 


WE  MANUFACTURE 

New  PEERLESS  COLLODIC 

FOR  FERROTYPES. 

PEERLESS  COLLODION, 

FOR  NEGATIVES. 

EUREKA  VARNISH, 

FOR  NEGATIVES. 

EUREKA  VARNISH, 

FOR  FERROTYPES 

ALSO, 

J.P.B.  cniorifle  of  Gold 


"WE 
ARE 
AGENTS 
FOB  THE 


WE  HAVE  TH 
HIGHEST 

Testimonials 

FOR  THE 
ABOVE 

TRY 
THEM 


TTOETHWEST 

FOR 

ENTREKIN'S 

PATENT 

OSCILLATING 

ENAMELER. 


H 

z 
>  m 

m  m 


H 
H 
m 


WE  ARE  HEADQUARTERS 
FOR  THE 

AM.  OPT.  CO.'S 

O  /APPARATUS 


AND  EVERYTHING 
'PERTAINING  TO  THE  ART  OP  PHOTOGRAPHY. 


REMEMBER. 

WE  POSITIVELY  WILL 
NOT  BE  UNDERSOLD  BY  ANY 
HOUSE  IN  THE  NORTHWEST. 


CHICAGO,  ILLS 


402 


ENTREKIN  ENAMELER  PATENTS 

Patented  May  20,  and  December  2,  1873. 


FIRST  PREMIUM  GOLD  MEDAL.  The  Scovill  Gold  Medal  was 
awarded  by  the  National  Photographic  Association  of  the  United  States  to  Wm.  G.  Entre- 
kin,  for  his  Oscillating  Enameler  for  Burnishing  Photographs,  Chicago,  July  16,  1874. 

FIRST  PREMIUM  SILVER  MEDAL.  Awarded  by  the  Franklin 
Institute,  of  Pennsylvania,  Philadelphia,  November  26,  1874,  to  Wm.  G.  Entrekin,  for  his 
Oscillating  Enameler.  •  ' 

I  have  guaranteed  the  validity  of  my  patent  to  all  who  make,  sell,  or  use  it,  and  have  covenanted 
to  defend  them  against  any  and  all  suits  for  infringement  by  the  following  guarantee : 

Whereas,    has  purchased  Photograph  Burnisher  No.  — ,  of  my  invention,  and 

made  under  my  Patent  No.  145,161,  granted  December  2d,  1873,  I,  William  G.  Enteekin, 

hereby  covenant  and  agree  to  warrant  and  defend  the  said   ,  his  heirs,  executors, 

administrators,  and  assigns,  in  the  use  of  said  Burnisher,  against  the  consequences  of  any 
and  all  suits  for  infringement  which  may  be  brought  against  him  by  the  owner  or  owners 
of  any  other  Photograph  Burnisher  whatsoever. 

In  Witness  Wheeeop,  I,  the  said  William  G.  Enteekin,  have  hereunto  set  my  hand 
and  seal  this  day  of  ,  A.D.  one  thousand  eight  hundred  and  .       WITNESS  : 

I  deny  that  my  patent  infringes  the  patent  of  Weston  &  McDonald  in  any  particular,  and  in 
support  of  that  denial  cite  the  following  opinion  of  eminent  counsel  : 

William  G.  Entrekin.  Washington,  D.  C,  Friday,  June  5,  1874. 

Deae  Sir:  Tours  is  just  received.  You  need  not  fear  any  trouble  from  any  parties  in 
regard  to  the  Weston  Machine,  Your  Burnisher  does  not  infringe  with  any  feature  of 
the  Weston  Machine  in  the  least  particular.  You  can  therefore  manufacture  and  sell  your 
machine  with  impunity.  Yours  truly,  C.  M.  Parks, 

Attorney-at-Law  and  Solicitor  of  Patents,  Late  Examiner  in  Patent  Office. 
Stansbury  &  Munn, 
Attorneys  and  Counsellor  s-at-Law,  and  Solicitors  of  American  and  Foreign  Patents, 
W.  G.  Enteekin,  Esq.  Washington,  D.  C,  August  7,  1874. 

Sir:  I  have  examined  reissued  Letters  Patent  No.  5281,  granted  February  11,  1873,  to 
Weston  &  McDonald,  and  your  Patent  No.  145,161,  of  December  2,  1873,  for  Photograph 
Burnishers,  and  am  of  opinion  that  your  Burnisher  does  not  infringe  the  Weston  &  Mc- 
Donald Patent.  Chas.  T.  Stansbuky. 
William  G.  Entrekin,  Esq.                                      Philadelphia,  September  3, 1874. 

Having  examined  Letters  Patent  No.  145,161,  dated  December  2,  1873,  to  William  G.  En- 
trekin, for  an  improvement  in  burnishers  for  photographs,  and  also  reissued  Letters  Pat- 
ent No.  5281,  dated  February  11,  1873,  to  E.  R.  Weston  and  T.  McDonald,  for  a  similar  in- 
vention, I  am  of  opinion  that  burnishers  constructed  according  to  the  Entrekin  patent  do 
not  infringe  the  patent  to  Weston  &  McDonald. 

Yours  truly,  Geo.  Harding,  Attorney-at-Law. 

PRICE  f  Cabinet  Size,  6  inch  roll...  $25  00        10  x  12,  14  inch  roll   $50  00 

LIST.  I4'4  size>  10  incn  ro11   40  00        14  x  17,18   "      "    75  00 

Each  machine  will  be  tested  before  being  shipped,  and  every  machine  warranted  perfect. 
Full  instructions  accompanying  each  machine.  Orders  and  communications  addressed  to 
the  undersigned  will  receive  prompt  attention. 

W.  G.  ENTREKIN,  SSTSSSi'SSS  EE  Manayunk,  PWla.,Pa. 

403 


1873. 


WILSON,  HOOD  &  CO.,  PHILADELPHIA,  PA. 


IF  YOU  WANT  THE  BEST,  BUY  THE 

LENSES. 

THEY  ARE  UNEQUALLED! 

APPLY  FOR  PRICE  LISTS  TO 

WILSON,  HOOD  &  CO.,  Sole  Agents, 

PHILADELPHIA,  PA. 


^,I7Y  ^SEARCH  INSTITUTF 

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